After that last attack Issei disbanded his helix shield and mash remove her shield also.
"That was close are you fine mash".
"Oh yes senpai that was close call but senpai how can you do all of this". Asked mash she saw many things and what Issei did was a level of a servant maybe even beyond.

"I wish we can stay and talk all day but for now we must find others mash believe me I will explain everything in time". Said Issei put his hand on her shoulders mash saw his eyes she blush away she can feel how warm he was but she snapped at her self to think clearly before anything they heard a scream.

"Kyaaaaaasshhhhh". Both Issei and mash become to run to the source of the scream to know who it was but for Issei he knew who she was.

POV change

A girl was running for her life there where a undead soldiers behind her trying to catch her.
"What is happening why those hunting me someone help". She sprint to the nearest wall she used her mage craft to shoot at them but to no avail she may kill 1 or 2 but then they become to multiply.

"Are you kidding me what wrong with this place". She wanted to continue running but then her foot hit something to make her lose her balance and fall on the ground she saw the undead approaching she prayed to anyone to save her then like her prayer come true mash comes and squash every undead she saw.
"Are you alright". Said Issei who was near her". Olga turned her face to see Issei she remembered him as the one who gave her a soul glare She was glad that at least he wasn't undead.
"Are you okay director". Asked mash who killed the last skeleton soldier.
"What happened".
"We are in a singularity fuyuki city 2004 from what the explosion happen we are here".

"So you become a demi servant what I want to know why tell now it happend".
"You may remember that chaldea was going to send a servant to this singularity in that time when the machine brought us the heroic spirit to come to me give me its power abilities and it's Nobel phantasm so now I'm now complete demi servant before we merged he wanted me to eliminate the cause of this singularity".

"So then this substitute commoner he is your new master". Said Olga mock Issei but Issei knew her he just sighed he didn't want to lower himself to her level he just ignored her make her angry but she let go then Issei watch become to flash and beep Issei saw it he press the button a holographic appear it was Dr Romani.
"Thank God you still alive can you all hear me".
"Dr Romani yes loud and clear". Said Issei make Dr node.
"Romani why did you take control of this operation".
"Director you still alive".
"Huh of course I am alive you idiot why the stupid question why are as a head medic section are in command where is leff"?
"Professor leff was in the center in the explosion I can't see any hope of him being alive". Said Romani made Olga shocked and horrified.
"No it can't be". Olga was about to cry but Romani continued.

"The reason why I'm in command in this operation it because there no one outrank me all of them are dead".
"Then what about potential masters what happened to the 47 Masters who were in the coffins"?
"All of them in critical conditionat this rate". Before he continues Olga snapped at him.
"Don't be a fool".make the Dr shut up.
"Transfer them to cryopreservation immediately ! Our top priority is there survival".
"I'll do it at once".
"Director..". Said mash but Olga cut her off
"As long they don't die it can be justified later I can't possibly handle 47 death on my back".
"Currently chaldea have lost 80% of it's power and capability once the communication is established with the outside world Ill request for supplies anything for the reserction of chaldea".
"Good work Romani archman I'm not happy about it but until I'm back you are in charge".

"Roger but this...a Demi servant a combination between human and servant I can't believe at time like this
". Romani saw Issei play with fou and mash was beside him Issei was knowing what will happen after this it become so problematic for him but it isn't the first time he may not admitted but he feel refreshed he knows there will be a servant nearby he can feel it.

"But starting right now Issei voldigoad and mash kyrielight will begin to investigate singularity f".
"I wish you all luck if anything happens please contact me".
"Hump you can send SOS but no one will save us from here".
"Director ..".In that Romani cut contact but Issei raised his guard up and he knew it would happen after a few seconds.
"Director are you sure about this we could wait for help instead".
"After this incident I can imagine the protest will happen with the association we can't come back empty handed". Olga grit her teeth and ball her first.
"Sorry about this but I will need your both help Issei and mash".
"Roger". Said mash Issei just give a small nod his eyes where seen waiting for something Olga notice it.
"Issei voldigoad is something happening you have been quite all the time".
"Didn't you realize something director a servant is nearby". Said Issei make both shocked but then mash felt something.
"Senpai is correct there a servant nearby". Said mash make Olga nod they begin to go where it comes.
After a while they where near a school but then they stopped when chains appear Issei just smirked she came.
"Well well well what we have here a unknown master and servant this gonna be fun the young one look delicious". Said a women with purple hair and yellow eyes licking her lips like a hungry cat yes it was Medusa.

" A servant but there no a master".
"This world have gone mad so seeing her without master is not crazy".
"So you are here turning everyone in stone for stealing there life force or eat them right". Asked Issei already know the answer.
"Your very sharp young man tell me why don't give up and let me turn you to stone don't worry I will make sure to treat you right". Said Medusa with sadistic grin.
"Medusa queen of the gorgon did you finish say your prayers because I stopped giving a damn". Said Issei with cold eyes make Medusa shudder hearing that name was something she didn't want to hear but why she felt her soul is in danger the more she look at Issei every part of her body tell her to run away but why.
"Who are you to say my name human". Medusa was holding her spear mash was about to block it but everyone stopped what they're doing hearing Issei Laugh.
"Hahaha hahaha haaa hahaha haaaa".

Everyone who heard the laugh felt the world become cold shivers was the only thing what Medusa felt she saw Issei eyes where changing from black to green and his hair from black to yellow.
"What so funny".
"It just I'm so excited it been a long time when I meet someone strong for that I will be serious a little". In that Issei grunt a little everyone felt his power become to spike Medusa take a step back mash was goospump from her master power Olga who feel his energy can say only one word a monster.
"Haaaaaa".

Issei whole being change his aura turn gold his power have gone by a mile Medusa in the first time felt fear her body no her instinct tell her to leave in instant Issei was behind her give her a punch send her near mash.
"Mash prepare your self".

"Hai". Mash used her shield to intercept her hitting her with the shield and send her to the skies Medusa who in air regain control use her hair as chain to capture them but Issei broke her chain like it was nothing he flew from his place and give her a powerful smack on top her face send her to the ground blood become to pour from her wounds
"Cough cough what are you you are not a normal human". Said Medusa bearly holding up.
"Who knows really but why do you care Medusa chan you begin first in this you know what will happen so why do you ask stupid question". Said Issei taunting her Medusa just had enough and become to use her nobal phantasm.
"Senpai she trying to use her nobal phantasm please step away from it". Said mash warning him don't want him to be hurt.
"Don't worry mash her nobal phantasm it's weak so don't worry". Issei just called Medusa Nobel phantasm weak Medusa was now fuming from rage a human call her weak even the most powerful Weapon she have weak why why do she feels scared her legs is shaking but why.
"To tell you the truth both your the first to even face like this I never seen someone like you but did you know if my spear hit you it can give you a scar can't be removed even when you heal". Then Medusa sprint at him think she caught him of guard but then Issei was holding her hand with 2 fingers.
"Impossible".
"Dear nothing is impossible". Issei then broke the lance to 2 everyone was shocked Medusa on the dirt not believing what happen her weapon broke she look at Issei who just return normal what was he we isn't normal her body was shuddering is this it her end.
"Well then it seems you out off fuel I would say you gave me a good spar but ohh well all have to end someday". Issei aura now become purple everything screamed death from it he caught Medusa from the neck but he didn't squeeze he put his arm in front of her.
"Any last word Medusa". Medusa just sit her see her life is gonna go there were nothing else she can do she missed with the wrong person mash and Olga was terrified from Issei aura was like it say submit or else.
"If that my last breath tell me what are you tell me your name". Said Medusa her last words.
"Well at least I can tell you I'm Issei voldigoad THE EVIL DEMON DRAGON GOD OF TYRANNY". Medusa was shocked she was infront a dragon god she now see how she are outclassed.
"Well then Medusa goodbye hope you be better in the after life before creation comes destruction HAKAI".

Mash and Olga see Medusa who scream from agony become to disappear in partical of lights there where a silence no one utter a word until now.
"Damn you killed her quick I'm impressed". Issei turn his face and see a man with blue hair holding a staff.

"Another servant". Said mash holding her shield infront of Olga and Issei.
"Wow now I'm not here to fight I come in peace". Said the blue hair man rising his hand in defeat position.
"Mash lower your shield he telling the truth". Said Issei make mash nod then Olga spoke she didn't forgot what happened to think beside her a being proclaim a god still make her uneasy now that explain his eyes and the fear she felt.
"Tell us what happened here".
"Straight to the point well..".
The blue hair explain everything how after the first grail war the grail was replaced by dark version of it and the one who guard it was saber and archer, caster try to swoop mash but Issei take her from his hand to his embrace mash felt flustered being in Issei embrace yet again the blue hair man laugh front his see Issei overprotective attitude.
"So what is your name you seem like caster". Asked Olga.
"First name Mario last name Mario, Mario Mario". Said caster make everyone except Issei sighed from his childdish antics.
"I'm serious now".
"I'm also serious". Before both starting to bite each other head Issei interject.
"cu chulainn Ireland child of light a Celtic demi god scatach pupel the bareer of the curse spear Gae Bolg". Said Issei stopping both Olga was surprised from Issei said and cu was impressed from what the boy proclaim god he got him good.
"Okay Ill bite is my name written in my back or something your the second one know about it".

"And let me guess the first one was saber the. One who defend black grail am I correct".
"Correct your smart boy or did you know that before hand".
"What you want me to say I know many things history is my virtue I don't forget anything history related".
"Wow we have a nerd with us but from what I see your super strong well why don't we go to end this with saber already".
"You took the word from my mouth let's go". Both now become to march Olga and mash follow both.

Time Skip

Now all was doing the scouting and Olga was doing some casting for a booby trap saber after this finished they all where ready but Issei stopped and summoned a bow shoot at the building make it explod

"You can come out Archer I can feel your presence". In that a man with white hair holding his bow with a grin.
"Wow I didn't know I'm facing bow man like me a master nonetheless".
"Ohhh is it now shiro emya". Issei said the name make the archer wide eye how did he know his real name.
"Surprised shiro even if you changed your aura is the same guardian or should I call you hero of justice". Said Issei with a smile archer was now infront a anomaly that know him well not just that but his past act how.
"Hero of justice I discarded that a long time ago it's surprising that you know me but I don't know you". Archer was now preparing his bow but then he jumped backward by caster blast.

"Sorry to broke both your bubble your opponent is me sorry kid but leave that for me". Issei just sighed discard his bow to pocket dimension.
"Don't die now caster we counting on you you two let's go". Issei entered the cave Archer would follow them but the caster was not letting him.

"Sorry whity but should not pass".
And both come to fight each other.
Issei was now running to see his next opponent he know who she is in the first time in his life Issei felt weird he first killed Medusa and taunting emya and now he will see saber or what he love to call her Artoria-chan after all he was in love with her don't you be surprised even Issei have something to like after that they stopped and see a mountain have black aura come from it.

"What is this". Asked mash.
"A dark reactor so maybe that the grater grail".
"My my last you all showed up". The three see where the voice comes from they saw a woman with a knight armor have purple aura surrounded her.

"Such energy".
"What a strange servant with a shield you will need to use it to survive with this sword I will see if you can defend yourself or not".

Artoria dash at amsh with her dark Excalibur mash was send back few meters but she still holding on in that a debris of rock was almost hit Issei and Olga but Olga use her ruin as shield now artoria try to slash mash shield.
"What wrong with you why don't you come forward". Asked artoria angrily her sword grow even stronger shoved mash couple of meters her shield was thrown from her hand now mash on dirt trying to get up Issei who see this know mash can do it he trust her capability but seeing her like that is tearing his heart he missed with history to much he need to let this played like the show mash need to enter her capability mash get up and get her shield and try to defend herself from artoria slashes.
"You have courage girl but can you still going on can you continue". Then the dark Excalibur become to emits more dark energy.
"Now try to defend yourself form this EXCALIBUR MORGAN".

Artoria shoot a dark beam from her sword hit mash shield she becomes to try to hold on as much as she can the blast from Excalibur was too much for her feet become to gave up she closed her eyes she may want to except defeat but then she feels a hand on top of her she see Issei behind her.
"Get up mash I know you can do it the heroic spirit didn't give you his powers for you to give up as a master no as your family I ask you to come forth with your resolve". Issei word was the catalyst for mash to force her feet to step up then she become to glow her power have returned to the max.

"Thank you senpai let me show you my resolve". In that mash activate her noble phantasm the shield become to glow

"Haaaaaaaaaa". Screamed mash make the artoria beam redirect at her.
"That shield is ". Before she can continue it hit her.

Mash lost her strength the Nobel phantasm depleted her Issei hold her tightly.
"You did good mash". But Issei knew it isn't over yet he see artoria still standing but she was wonded mash try to get up but Issei tell her it's over in that cu came and use his Nobel phantasm on her put artoria in a cage.

The cage burn itself meaning it worked artoria lost.
"Phew good you all standing".
"You took your time".
"The archer was pain to deal with".
"Can't fault you in that". In that they see artoria who stands but it seems she had enough
"Victory for the power to protects indeed now it's is as expecte". Then artoria had a smile.
"Ultimately fate may change whatever the outcome the fact I face it alone remains".
"And what do you mean by all that you are trying to tell us something". Asked a intrigued caster.
"One day you will know the answer Ireland child of light". Before she disappear in partical Issei interject.
"Artoria". Said Issei make artoria look at him.
"Mark my word the next time we see each other don't ever think of leaving I'm excited to fight you next time king of the knights". Said Issei with a smile artoria alter looked at him with a smile she have to get the kids props to be bold she can feel it in him while disappearing .
"May I know who you are".
"Issei voldigoad".
"Then I will remember the name next time and the grand order out battle may have ended but the grail had begun".
"Hey wait I have more questions what do you mean by that". Said cu but he sees himself disappearing his time has come again.
"Kid young lady I leave all this to you".
"We will meet again cu".
"We shall if there is another war please summon me as a lancer ". In that cu disappeared.
"Anomaly is gone master the war is over". Said mash and a piece of the holy grail comes to Issei hands he then he see Olga he knew what to do.
"We won this battle thank for both you you too director". Said Issei with a smile make Olga have a tight blush it's was the first time one comment on her.
"That was a rough one we did it congrats mash for unlocking your potential the shield open for you even if you don't know the name it respond to you wow now that over it is like fairy tail if you ask me but a Nobel phantasm with no name let me think for what to name it hmm I got it why not lord Chaldea you know it more then anyone".

"Hai lord Chaldea s it is". Issei pat her head knowing how she happy about it but then there where a clap Issei knew it who it was yes Dr lev.
Olga who saw him she was happy know he is alive she become to run to him but what he said to he broke her how she isn't dead yet after he used magic under her office that caught his conclusion that her physical body is gone because she can't rayshift but now when she is dead she was able too Dr leff tried to take the grail but Issei was not letting him.

"Sorry but the grail going no where lev". Said Issei put seal on it.
"Well what a surprise subject 48 you surprise me greatly he then snapp his finger make Olga hover over the ground he then use his power to make Olga touch the reactor it was her wish to be near it he would succeed I mean would but then.
"Universal pull". Said Issei make Olga fly toward how she was in his embrace again.

"Dr Lev don't even try to do something go to your general and tell them there fate are sealed". Issei rinneagan eyes activate it mean business.

"Hmmm you may win this subject 49 but now this only the beginning". In that he disappeard.
"You okay director". Said Issei who saw Olga who didn't let go she was scared she saw her life flash through her eyes she thankfull Issei saved her but she knew she would die if they return.

"Don't worry you want die". Said Issei she saw his eyes it was like see death itself but she can see he was sincere in that Issei contact Dr Romani to get them out after flashes they return.

Time skip

Issei wakes up and sees himself in bed he see fou beside him and takes him to the Chaldea facility he saw mash in her sciences outfit.
"Good morning senpai". Said mash with a smile Issei just hugged her he glad alright but he hear a cough he see Dr Romani and some staff hold there voices.
"Good thing your safe and well".
"Is everyone okay".
"Yes the masters is good but need rest but for director". Said Romani his head low.
"Romani raise your head don't worry I can get her back". Said Issei shock them.
"How".

"Just I need a blood sample do you have it". Romani didn't understand but he go to the lab and give it to Issei who open a scroll and put the blood in it.
"Then begin to do a hand sign".
"Edo tensei no jutsu". Said Issei clap his hand together a tomb raise.

came a reanimated Olga make everyone shooked and scared doesn't believe what they see.
"Renni rebirth". Then Issei touch Olga body who become to get steam off her her body felt like alive it open her eyes she see herself doesn't believe herself her body is the same she see Issei mash and Romani and the others she become to cry she returned to the land of the living.

"Like I told you director I brought you back". Said Issei Olga then hugged him tightly crying saying thank you over and over.
"Oh thank you thank you Issei voldigoad". Romani see this doesn't believe his eyes he saw many crazy thinga but this was not one them.
"How did you do it".
"Life and death is game for me Dr you talking with a god after all". Romani still can't comprehend what he heard and saw.

"Senpai you told me you will say what you are, I don't want to force you if you don't want too".
"No mash it's alright".
"Then tell us Issei what are you". Even Olga who was still hugging him wanted to know also having a god isn't that bad after all.

"Well to keep it short and simple for you all I'm come from a word that age of the gods didn't end I was a human once but a accident happen make me what I am now I know of this world from a series called fate". What Issei said shocked them wait that mean he knew that will happen why didn't he say anything.

"If you all ask me why didn't I say anything please believe me if I did there would be more damage then goods changing fate isn't a game changing a small thing can be more destrubing then other". All didn't say anything Issei was right if he changed anything they would be in deep shit.

"So what are we then". Asked Romani.
"You all alive like I see you in my world you are a fiction but here you are real hell even my world maybe a fiction in another world ever think about that". Romani think about it he can't fault Issei logic but it was too much for him the taught to be seen and know how story begins and ends.
"So you know what will happen next".
"Yes I did that why I came here to see better outcome like Olga for example she supposed to die but I saved her life". Olga here was shocked so she was supposed to die but Issei changed that she was more confused than ever but she is still glad she is alive.

"So that why you knew the servant names". Asked Olga.
"Ohhh believe me I remember them from top to bottom everyone's strength and weakness and their Nobel phantasm".

"But I'm sure it was not the only reason you came here". Said Dr Romani is still processing the information
"Your right it is not the only reason I had a vision in this world I want to know why that's why I make sure to help you all in this for the sake of this world and mine I'm sorry keeping this secret from you all I hope you all forgive me". Issei just bowed his head all was touched from Issei words if they where from his choose they may did the same mash raise his head.
"Please senpai we don't blame you for it we are surprised and thankfull for you saving us I'm happy meeting you". Mash said with a cute smile Issei heart beat fast.

"So tell me how is your word". Said Romani he was now intrigued.
"Well my world is state from not all human know about the supernatural and human born with sacred gear and the supernatural all still exist like Egyptian Greek North pantheon etc ...
"What are sacred gears". Asked Olga intrigued.
"Sacred gears is a object made by the bibalic god some are powerful and some are for defense but only human and half human can wield them".
"Why"? Asked mash.

"For protecting humanity from supernatural if they are in trouble.
"You said you where human before what happened". Issei eyes darken all saw it seems it's a dark memories.
"Sorry senpai I didn't mean to make you remember".

"No mash it's alright let me tell you all". Then Issei become to tell them about his life before supernatural how his ex parents did to him to be killed by fallen angel but she was force to do it for him to activate his gear and being forced recarnated to devil by a period hair and his adventure in different world and fighting Loki the god of mischief". The Dr the director and the masters who hear this was in awe they felt sorry for him for what his parents did they where angry for that devil whore did but they are happy for him to have found people who loved him and take note for not make him angry.
"It seems you had it rough". Said Romani hold his shoulder.

"Well at first but I meet a woman changed my life with the others". Issei hold his mouth why he open his mouth.
"Others". Said Olga and mash at the same time.
"Nothing forget what I said ".
"No no say it what others". Said Olga holding his shirt.
"Yes senpai tell us". Said mash with a smile but her eyes say another thing.
"Okay for me in supernatural men do have a harem you could say I have one a bigger on in that". Issei said the he pray to someone to help him Olga heard this had a smile no no no it wasn't a normal smile but a lustfully smile.

"Ohhh is it then so you wouldn't have a problem with me then".
"Huh". Issei before asking what she meant she kissed him in the mouth make him stager and all who watch have there mouth his the ground after that she stopped and look at him.
"Then Issei hope you take responsibility". Said Olga with a smile that told him she was serious Issei was shocked he didn't dream that would happen but he feel arms behind him he saw mash and no she did something he didn't act fast mash kissed him also okay Issei is fucked now after that she stopped.
"Senpai you also have to take responsibility for me also". Issei was now feel like his life was turning he didn't know if it was for the best or the worse.
"Ehhhhhhhh". Screamed all who witness this what will happen to our hero in the future stay tuned to next time in Issei the dark dragon god.