Issei and the others are at the Kyoto station waiting for the train to arrive while Yasaka and Kunou along with Serafall are with them saying there goodbyes.

Kiba: "We'll be going now. Thank you for taking care of us."

He, Saji, Asia, Xenovia and Irina bow down to them.

Azazel: "Thanks for letting us stay here Lady Yasaka."

Rossweisse: "Thank you for your hospitality."

Yasaka: "It's no problem. I wanted to thank you as well."

Kunou: "Will you come back and visit here Kiba?"

Kiba: "Yes I'll come by and visit."

Yasaka: "And thank you for saving for saving me Issei, especially last night.~"

Issei: "No problem Yasaka. Just be careful next time. We don't know if they'll strike again."

Then they heard the train arrived.

Issei: "Looks like our ride is hear."

Yasaka grab Issei's collar and smash there lips together. This made Asia, Xenovia, Irina, Saji and Kunou shock while Kiba and Serafall just chuckled and Azazel smirks.

Yasaka: "Consider it as my farewell gift.~"

Issei: "Then I gladly accepts."

Everyone climb aboard on the train while Yasaka, Kunou and Serafall wave them goodbye.

Kunou: "Is this mean that Issei's going to be my new Dad?"

Yasaka: *Giggle*"If he accepts it dear. And I see the way you look at Kiba.~"

It made her blushed a little while denying it.

Kunou(Blushed): "N-N-N-No i-it's not what it looks like! I-I-It's not like I-I r-really like h-him or anything!"

Yasaka: *Giggle*"Don't worry Kunou, he seems to be a nice guy."

Serafall: "Kiba really is a nice guy Lady Yasaka. I'm pretty sure that he will take care of Kunou-chan."

Time Skip

After everyone reaches the Kouh Station, Azazel just teleport back to his apartment while Issei and the others walk back home.

Issei: "I hope you guys didn't destroy the mansion while I'm gone."

Kiba: "The President and Trihexa would be very mad if that happens."

Asia: "They really miss you a lot."

Xenovia: "Where you've been for months?"

Issei: "I was in Olympus."

Irina: "I wonder what would the Rias and the others react if they saw you."

Kiba: "I sure that they'll be running towards him and hugging him tightly that would make his face blue."

Rossweisse: "There's only one way to find out."

They finally reach at the mansion and some maids open the gate and welcome them back.

Maid: "Welcome back master."

They open the doors for them and they went inside. Trihexa, Kuroka and Koneko walk out of there room and went to the living room to welcome Kiba and the others back. But when they got there, they were surprise and happy to see Issei.

Kuroka: "Issei!!"

Trihexa: "Master!~"

Koneko: "Onii-chan!!"

They run towards him and tackle him into a hug, making them fall on the floor.

Trihexa: "Master! I've missed you so much!!"

Koneko: "Please don't leave again Onii-chan!"

Issei: "I missed you too girls."

Then finally, Rias run at the living room because she heard some screaming.

Rias: "What's going on? Is everything alri-"

She didn't finished her sentence as she saw Issei. She put her hand in her chest and tears where coming out of her eyes.

Rias(Tears): "I-Issei? Is that really you?"

Issei: "I'm home."

She runs to his arms and embrace him by placing his head into her chest while crying her eyes out.

Rias(Crying): "Issei! I knew you'd come back!"

Issei: "It took longer than I thought it was."

Rias(Crying): "At least your home here with us!"

After a few minutes, Rias finally relax and Issei tell everyone about his journey at Olympus.

Issei: "So that's how I found Mount Olympus and... The last time I will see my Father."

Everyone was silence for a couple of seconds and but Issei light up the mood again.

Issei: "But Father trusted me with this power, and I will not fail him. It will bring me shame if I do failed."

Asia: "Your not going to fail Issei-san."

Xenovia: "Yeah, your unbeatable."

Kiba: "And we haven't seen you lose even once and we would like to keep it that way."

Trihexa: "And besides, nothing in this world can defeat you Master.~"

Rias: "They're right Issei. No matter what situation you've been, you always come out on top. And always will be."

As they where having a heart warming chat, a red magic circle appeared on the middle and Sirzechs along with Grayfia comes out.

Rias: "Brother? What's wrong?"

Sirzechs: "We got trouble. The Underworld is under attack and we need all the help we can get!"

Everyone was shock at Sirzechs statement.

Rias(Shock): "Under attack?! By who?!"

Sirzechs: "We don't know, but we saw Cerberus there with the enemies!"

Rias: "Then let's go everyone!"

Everyone: "Yes President!"

Sirzechs created a large magic circle on the ground for everyone to get in. When they got out, they saw Devils, Fallen Angels and Angel are working together to attack the enemies.

Akeno: "Looks like this is serious. All three Factions are here."

Kiba: "But what are the enemies?"

Asia: "Kiba-san, look out!"

He look to his left and saw an undead Satyr jump up to attack him, but out of nowhere someone dash in front of Kiba and block the satyr and cut it in half.

???: "Greetings, is everyone alright?"

Xenovia: "Who are you?"

Arthur: "My name is Arthur Pendragon of team Vali. We come to help you."

Kiba: "Team Vali?"

Vali: "That's right. He's part of my team."

They all look behind Arthur and saw Vali and the rest of his team. Rias and the others ready there magic and weapons at them but Sirzechs block them.

Sirzechs: "Calm down everyone, they may be our enemies but we have even bigger problem here and we need all the help we can get."

Rias and the others put there magic and weapons down and calm down.

Rias: "Alright we'll trust them. For now."

Sirzechs: "Vali, get your team help evacuate the civilians first. After that, go to Azazel. He might need your help."

The all nodded and headed out.

Sirzechs: "Rias, you and your Peerage go to Siaraorg, they might need help."

Rias: "What about Issei-"

She noticed Issei was already gone and fly in the middle of the battle field.

Rias: "Let's go everyone!"

ORC: "Yes President!"

Issei's POV
(Play the song on the top)

I fly towards where the battle is happening and I saw some Devils, Fallen Angels, and Angels attack some undead Satyr, Cyclops, Chimera, Harpy and many more Greek monsters.

I grab the Blades of Chaos and retracted my wings. I let go of the Blade and extended the chain, as I started to free fall, I threw my Blade at one of the Satyr and I grapple myself to it and cutting his head off.

Issei: "I will handle this! All of you get out and help the others!"

I said it to the Devils, Fallen, and Angel and the all nodded and fly back to the others. I look up front and saw a Cyclops was about hit crush me with it's wooden club.

I side roll his attack and stab him in the arm and climb into it's back and stab it in the neck

The Cyclops roared in pain as I keep stabbing it in the neck and it's swinging it's club around the Satyr, killing them.

The Cyclops is trying to reach it's hand to grab me but I jump down to it's face and grab it's eye with one hand and pulled it out as the cyclops bleed to death.

I put the eye on my back and charge at the enemies. I swing my Blade left, right and slam both of hem into the ground creating a small explosion.

One of the Satyr almost hit me with it's sword by I grab it's wrist and leg and used it's body as a shield from the incoming arrows. I put the body down and pulled it's head of and I run in the middle where they were able to stop me in the tracks by crowding me.

All of them was able to crowd me but I summon the Nemean Cestus to blow them away.

One by one they rush at me but I punch them and blasting their entire body. Then I saw Trihexa in her Dragon form shooting some Cyclops as she fly around the battle field.

I slam the Nemean Cestus on the ground creating a shock wave blasting all in the way while knocking the others off balance.

I was caught off guarded from behind when a Cyclops grab me by it's hands and trying to crush me. I couldn't move my hands because it was gripping me real hard, so I used my Rage of the Titans to cover myself in blaze making the Cyclops to let go.

I launch the head of the Nemean Cestus at the head of the Cyclops, grappling myself towards it and punch the head hard, destroying it into pieces.

All the enemies over are now dead, now I need to get back to the others and them. But out of nowhere, a Chimera came running and wrap it's tail around me and drag me away and throw me. When I got up, I saw a Centaur running towards me with it's spear pointed at me.

I used the Golden Fleece to block him and used the momentum to throw him over. I rush towards it while his down and stab one of my Blades into his stomach and opening it, making all the intestine fall out until he dies.

Then the Chimera's Snake tail tried to bite me but I used the Artemis Blade and cut it. Then the Chimera stands up and the Lion's head starts to spit fire on me. I jump out of the way but the Chimera jump high and hit me in the stomach with it's horn, piercing right through.

It swing it's head around tossing me into the boulder and it stands up again and the Lion's head roared.

Issei: "You Bastard!"

I grab the Blades of Chaos and rush towards it. The Chimera spit fire on my path to block me but I throw my Blade at it and grapple towards it. I stab it's left chest repeatedly until I stab it's both eyes, killing it only leaving the goat head.

The Chimera quickly run at me and tried to stab me with it's horn again. I open the Guardian's Shield and slam it's horn to the left making it stumble into the ground. I stomp at it's head and broke it's horn and stab it in the eye killing it.

Then I saw Rias and the others flying towards me.

Rias: "Issei!"

I put the Blades of Chaos on my back and Rias gave me a spine crushing hug.

Rias: "Issei are you alright?! Are you hurt?!"

Issei: "I'm fine Rias. No need to panic."

I then saw Sona, Tsubaki and the other SC flying down at us.

Sona: "Issei! Rias!"

Issei: "Sona? Is everyone safe?"

Sona: "Yes. Everyone has been evacuated aside from us."

Akeno: "Then let's go with the others."

We were about to leave but ground started to shake making everyone fall off balance.

Tsubaki: "W-What's happening?!"

Sona: "This isn't good."

We all heard a loud Roar and the ground starting to open a huge crack.

Issei: "Everyone get out of here! Fly away!"

All of them open their wings and fly up. We saw a giant hand crawl out of the ground making everyone panic.

Saji: "What the hell is that?!"

Koneko: "it's a hand, can't you see?"

Then another hand came out of the ground until it's whole body crawl out. It was a giant Cyclops with horns and it was about 30 meters high.

Issei: "It's a Cyclops! But it's no ordinary one!"

Kiba: "What do you mean?"

Issei: "Cyclops isn't tall as that one. I'm guessing that this one... is a Titan."

That made everyone shock that this Cyclops is a Titan.

Rias: "I thought that the Titans are all gone?!"

Issei: "That's what I thought too. It seems that this one hid itself somewhere."

Trihexa: "Why would a Titan be hiding?"

Issei: "Don't know, don't care. Cuz I'm going to kill it."

I saw Vali in his Balance Breaker along with Sirzechs, Azazel and Michael flying towards us.

Michael: "Good Lord! A Titan!"

Azazel: "I thought those Giants were extinct?"

Sirzechs: "It seems that this one is the last of it's kind."

Issei: "And he will follow Gaia in the Pits of Tarturus!"

Michael: "Can we make it as an ally instead?"

The Titan saw us and grab many rock and throw it at us. Asia was able to create a barrier around us in a nick of time.

Issei: "You were saying?"

Vali rush towards it but only to be grab by a Harpy distracting him for the Titan to grab him. The Titan was putting a lot of pressure on it's grip at Vali and he's Balance Breaker is starting to break.

Vali(Pain): "AAHHHH!!"

Bikou: "Vali!"

He fly at the Titan's hand with his flying Nimbus and slam his Bo Staff at the hand but the Titan felt nothing. He kept slamming his staff along with his other team helps him. Arthur brought out his Holy Sword and a blond girl with a Witch's Hat shooting it with her magic.

Azazel: "Even they're combine attack did nothing to that Titan!"

Michael: "We must help them!"

Azazel, Michael and Sirzechs combine their power to attack the Titan but it used it's free hand to block it, shocking everyone.

Rossweisse: "Even the combination of the great three power didn't do anything to that thing?!"

Kuroka: "Looks like we're all in big trouble."

I fly towards it hand and stab my Blades on it and causing it realease Vali. Bikou caught Vali and fly back to the others.

Issei: "Get out of here!"

Rias: "Issei!"

Issei: "Rias Go! I'm the only one who can kill this thing!"

The Titan is trying to crush me with it's thumb and index finger as I resist to pressure.

Rias: Issei!!"

Issei(Grunting): W-What are you still doing here?! Get out already!"

Sona: "We can't leave you here!"

Issei(Grunting): "I didn't asked your permission! Trihexa! Get everyone out of here! That's an Order!"

She was hesitating at first but she comply.

Trihexa(Tears): "Yes Master."

She change into her Dragon Form and cast a barrier around everyone, carrying them with her claws and flying away.

Rias: "Trihexa, stop! We can't leave him!"

She didn't answer her, she just continue on flying away and Rias tried to cast her Power of Destruction but Sirzechs stop her.

Sirzechs: "Rias stop it! We know how you feel, we too don't want to leave but we have no choice! You see what that Titan did to our attack right?! Only Issei has the Power to stop it! We just need to believe him and he will come back!"

Akeno: "He's right Rias. I know Issei can do this!"

Rias(Tears): "B-But I-."

Kuroka cast a purple fog on her face to knock her unconscious.

Kuroka: "I'm sorry Sirzechs-sama. But I must do it."

Sirzechs: "I understand. It was necessary."

I look at them that they're finally away from me, and now I can let lose. I push the thumb and the index finger of that Titan to give me time to grab the Artemis Blade and cut it's finger off. The Titan scream in pain, throwing me into the sky.

The Titan saw me falling and ready it's fist to punch me but I lean to the left, missing me and I throw my Blade to one of it's finger to grapple down to it's palm. Then a bunch of undead Satyr came out of nowhere and start attacking me.

I grab the Blades of Chaos on my back and start swinging it left, right and slam both of them down. Then I noticed that Titan was going to slam it's other hand on me.

I was resisting it's hand to not crush me. I push a little further to grab the Blade of Olympus and stab it in the palm, making it roar in pain again.

The Titan closed it's palm with it's finger, blasting me towards it's face. I used it the punch it in the eye with the Nemean Cestus making a loud roar. I jump down to it's tusk where it's hand is trying to grab me.

I throw my Blade on it's finger to grapple myself behind the hand. I used the Spartan Rage along with the Nemean Cestus to punch its hand piercing it into the tusk. The Titan roared again and trying to get it's hand off it's tusk but I throw the Leviathan Axe to the tusk, covering it with ice so it's hand won't move.

I jump on the other tusk and throw my Blades on it's other hand pulling it to stab it in the tusk. I was able to pierce the other hand making it unable to be used. I climb up to it's face and look at it's eye.

I grab the Blade Of Olympus, raising it at the sky charging it with lightning. Then I stab the Titan in the eye.

The Titan let out a very loud roar that everyone in the Underworld can hear it. It starts to struggle to shake me off but I charge the Blade with the Power of Hope shooting a beam of energy right through it's head until he fall down on the ground dead.

I put the Blade of Olympus away and jump off it's head. I was about to walk away but I head something moving. I look behind and saw a small Troll climb out of the eye. When it saw me, it tried to run away but I throw the Spear of Destiny on it's leg, destroying it.

It tried to crawl away but I threw the Leviathan Axe on the other leg, freezing it in place.

Issei: "Who are you?"

Troll(Pain) "I thurilrag gulueveum ushelrag gorou!"
Translation: "I will never tell you!"

I grab the Nemesis Whip and stab it's hands while I cast lightning on it.

Issei: "I won't asked again."

Troll(Pain): "Gu'rat ushhuth ininuth thurhug shrakroughakum ushhuth ushitan!"
Translation: "I'm the one who brought the Titan!"

Issei: "Why?"

Troll(Pain): "Ushug ishestrozag ushhuth lugnderworlmar ashug i ilabag ululuth gut!"
Translation: "To destroy the Underworld so I can rule it!"

I stand up and stomp on it's head, destroying it into pieces, killing it. I spread wings and fly out of here and head back to the others.

When I got there, I saw everyone was waiting for me while Sirzechs, Azazel and Michael are planing to restore the Underworld. I fly down and when they saw me, they came on running.

Akeno: Issei-kun!"

Trihexa: "Master!"

Koneko: "Onii-chan!!"

Sona/Tsubaki: "Issei!"

Asia: "Issei-san!"

They all give me a group hug while Sirzechs, Azazel and Michael behind them watching.

Azazel: "Told you he did it."

Michael: "You didn't say anything."

Azazel: "Hey I said it before we left. Right Sirzechs?"

Sirzechs: "I have no idea on what you two are talking about."

While the Azazel and Michael are arguing, I saw Rias running out with Grayfia.

Rias(Tears): "Issei!"

Everyone else made way as she runs and jump at me, embracing me into a hug.

Rias(Crying): "Issei! Please don't leave me again!"

Issei: "I'll try not too."

She grab my cheeks and give me a passionate kiss for ten seconds.

Rias: "I missed doing that.~"

Issei: "Now that everything is over, we got time for ourselves now."

Author's POV

Everyone in Issei's Harem starts to kiss him for missing him in months. The three leaders proceed they're plan on restoring the Underworld to it's former self.

As all of them happily celebrating they're Victory, A spectral wearing a long dress woman in a distance watching at Issei.

???: "The day will come, for our time to meet. Son of Spartan."

With that, she turns around and walks away as she slowly disappearing.