(A/N: I hope you enjoy the book, to make things clear in the book, this is about 2 years after the last war and Nico is 16 as everyone else is the age they would be 2 years after the Last War. Nico doesn't have a crush on Percy anymore, or anyone for that matter. So yea, now that it's been cleared up, enjoy the story.)

Chao's Assassin

-|Chapter 1|-

On planet Alkaline, people walked the streets in the cold night. The festival was once again up and running, successfully distracting the subjects of Alkaline. A lone figure stood on the rooftop of one of the highest buildings. Their body crouched, eyes surveying the scene in silence. A mask covered their face from any possible looker that looked upon the sky. Their body covered in a skin tight black leather body suit for flexibility and had a black cloak with a hood on.

Her eyes narrowed on the man walking into the crossway alley, out of sight for anyone else besides herself. She kept her face emotionless behind her mask as she skittered on the roofs, silently jumping from building to building flawlessly.

She stopped on top of the building on the side of the alley. She crouched on the building ledge. Slowing crawling on the wall, which should be impossible if she hadn't had her equipment and special gloves. Her cat tail whipped behind her, twirling as she silently stood on the floor behind the target. She walked in a straight line as her cloak flowed gently and her tail whipped silently. Her face stayed emotionless behind her mask.

The target looked over his shoulder, finding nothing but empty air. He looked back only to stumble back as a pair of eyes stood a few inches in front of him. His eyes widened in fear for the woman gripped him from his neck and pulled him to his feet. She silently pinned him to the wall by his neck with one hand.

Her pure white eyes stared daggers into his tainted soul. With a strange melodic voice a voice was carried in the wind.

"It's time for you to...sleep..."

Her only visible part of her face was her lips, and she suddenly grew huge raven wings on her back and her eyes grew golden as she slit his throat. The man dropped dead on the ground. The woman took a feather from her wing and gently stuck it on the man's chest. She walked away calmly and back to the rooftops as her wings disappeared from sight and she disappeared in the shadows of her cloak in the midst of the night.

~~~~~~~~~~~~~~~•

In the capital of Alkaline, a group of friends sat together on the grand castle of Chaos' roof. They laughed and had short conversations, enjoying their new life on the planet.

They were group A of the Chaos Army, former demigods of Earth. They were chosen to be a chaos solider. In highest rank of the army, group A did not know why they were in Group Alpha. But something told them it could be the fact they all knew each other, but deep down it wasn't that either.

For some they lived on planet Alkaline for about 2,000 chaos years, they knew they were immortal and their friends on earth probably died off by now, sadly. Just not the fact that 1 earth year was actually equal to 1,000 chaos years.

Their names were Bianca Di Angelo, Zoe Nightshade, Castor, Charles Beckendorf, Luke Castellan, Silena Beauregard, Ethan Nakamura, and Phoebe.

The Chosen Fallen Heroes of Earth, Group Alpha.

The group quieted down as they saw a figure emerge in the middle of the street in front of the Castle Chaos. They stood with a mask on their face and pure white orbs piercing through the eye holes. The Group Alpha stood up alarmed, having to never see the figure before.

"Do you know who that is?" Luke whispered to Bianca and Zoe, as they've been here the longest out of the group.

Bianca and Zoe glanced at each other, and then to the group.

"You better hope that you didn't do anything illegal lately!" Zoe whispered harshly in proper English to Luke, Ethan and Castor.

The three looked at each other.

"Why?" They asked wearily.

Bianca rolled her eyes, putting her arms crossed over her chest, she looked them over.

"Because that's Chaos Assassin, she doesn't let anyone see her unless someone is going to die, or worst, but that's never really happened." She said matter-of-factly.

The group looked at the figure on the empty street. They looked as they saw that the Assassin was on a rooftop this time, on the right of the street. Phoebe watched her structure and balance as the assassin moved gracefully.

"Did you guys know that she's supposedly the one giving us order and is Group Alpha Leader?" Silena said absently.

They glanced at her shocked for a moment before turning back to the Assassin.

~~~~~~~~~•

The Assassin stood on the ledge of the rooftop. Analyzing her supposed 'team'. She heard with her black cat ears on her head and found out that the girls of the group were smart, and a bit intelligent.

She knew they were analyzing her as well. Seeing as she never took a direct appearance unless someone was going to die. This time was different though. She'd need to break some of her own rules. She walked up tauntingly to the group from jumping rooftop to rooftop silently. She continued to run up the wall of the side of the grand castle, considering her black combat boots was especially edited for that 'feature.'

She shocked them when she gracefully flipped onto the rooftop and stood next to the group. The group had turned around, their backs to the street and watching as she stood still with her hands clasped behind her back, her face emotionless behind her mask. She looked at them with pure white orbs that somehow twinkled in the slightest amusement.

"I have a mission for you, Group Alpha."

Her voice was like a twinkling melody in the wind, yet serious and stern as her mouth somehow remained closed.

The group's eyes widened. They knew that this was worst then her usual assassination. The group straightened. The assassin chuckled darkly and humorously.

"It truly fascinates me to see how my own men and women peers seem to be...afraid of me."

Her voice suddenly sounding haunting.

"No matter," she said decisively, "It's time for a mission I know particularly some people actually take seriously. You and I will be traveling to Earth. It seems like Order loves to play a game called favorites and decided he wants to destroy Earth in a war."

Group Alphas eyes bulged out of their heads at the information. The assassin had continued on as if she didn't see their reactions.

"This mission was given directly by Lord Chaos, and we have to be careful. Something you may be wandering for a while is of earth. It's been years since the last of you came here. Bianca and Zoe, it has been years longer or so when they last saw you on your quest to save Artemis. For the others of you it would range.

"Something I know you have thought about is why you are Group Alpha. It's simply because you are the only ones in the whole army besides Group B that has been brought back to life. That and also because I was the one responsible, not Chaos or any general. Chaos had given me his permission to do such and it is why you are breathing now. Now go and pack as we leave tomorrow morning by portal. Good night Alphas."

The assassin disappeared in the shadows and darkness in her cloak. A second later she appeared at her base and packed her weapons and such inside her duffle and sat it next to her bed as she closed her eyes and fell asleep with her mask on and cloak hood up.

~~~~~~~~~~~•

Group Alpha looked at each other flabbergasted. The assassin didn't kill anyone, and now they are going on a mission to earth is with their never seen before leader? Order is rising as well and they suddenly got serious.

"Let's go." Bianca said as she left the rooftop, going inside the grand castle.

Ethan looked at her. "That's all you have to say? We basically just pissed our pants because of an assassin and all you say is 'Let's go'?"

Bianca stopped abruptly making Charles grip Ethan's shoulder warningly.

"What do you want me to say? We just got a direct order from our leader and we need to follow it. Aren't you, at the least, excited about going home to camp?" Bianca said sternly. And she left in the shadows before anyone said anything.

Zoe looked at the group and stood next to Phoebe, "well, you heard her, let's go pack."

They clasped their hands and teleported elsewhere.

(A/N: The group has all their powers from before they died and a few extras.)

~~/next morning\~~

The group stood awkwardly in the middle of the ball room of the castle of chaos. Where all soldiers in the army lived. Even though of its name, the creator Chaos does not live there. He lives somewhere else, some say in the Void but no one truly knows. People have seen Chaos before, 4 times each year in fact. But after that, he simply vanishes until next time.

Some think and say of rumors that only The Assassin spoke to Chaos in other times and that she knows where he goes, but no one sees her long enough to stop her and speak to her. The group looked up at the sudden movement on the roof, jumping up about 3 feet in the air after seeing Chao's assassin upside down on the ceiling, her cloak and mask somehow still covering her face and body.

She jumped down from the 30 foot high ceiling and landed gently on the ground that should be impossible, but the group seen other things as well.

She stood gracefully and flexibly, as if ready for anything. Her pure white orbs looked haunted at Group Alpha. Her voice suddenly cut through the air and her mouth remained closed.

"You may call me D.A on this mission. And I have a slight...surprise for you once we reach earth. So you must wear theses," she snapped her fingers as a spark was seen between them. "Those cloaks will hide your identity, and if anyone looks inside, all they will find is darkness. Of course the magic won't work for each other in Group Alpha; you will see each other perfectly. Now," her eyes somehow twinkled in the faintest amusement. "Let's visit Earth."

The group felt a blanket of cloth wrap around them and found cloaks upon each other. The group looked up at the assassin only to find a portal in her place. The group looked at each other and back to the portal.

Silena laughed nervously, "Well, YOLT right? We are immortal anyways." She then ran and jumped into the portal, her husband Charles running after her.

The remaining looked at each other and shrugged, they ran into the portal next. The portal closing after them, as they landed in the Olympian throne room.

~~~~~~~~~•

D. A stood in the shadows, watching as her soldiers jumped out of the portal, landing in the throne room.

The Olympians stopped their petty arguing to look at the group alarmed. Hades and Hestia looking interested at the group as well as Athena and Apollo.

The tense air was cut through when Zeus stood with his bolt raised.

"Who are you?! Why are you in MY throne room?!"

The group stayed quiet, a voice in their heads telling them not to answer, and they did not. Zeus raised his bolt to shoot, thinking these may be enemies from the coming war. His move was struck short when a voice cut through the air.

"Zeus, do us all a favor and put your toy down. We don't need anyone throwing a tantrum here do we?"

The Olympians moved their alarmed gaze towards the cloaked figure wearing a mask, leaning against a pillar in the room. Her mouth remained closed and her appearance a mystery. Her pure white orbs shocking the gods.

Zeus threw the bolt at her, his pride and temper getting in the way of his logic. The Group Alpha looked at the figure alarmed and in shock as she caught it with one hand calmly and twirled it, in between her fingers; the power not really affecting her.

"You are so lucky someone important wasn't here to see that," she deadpanned, "Now, is that anyway to treat your allies in this war? Lord Chaos has given you us as an ally and you try to shoot down the leader?" She twirled the bolt before making it disappear and reappear next to Zeus feet.

She walked gracefully in front of Group Alpha, bowing at the waist mockingly. Athena was analyzing all of her movements. Artemis looking at her and thinking of how good she could be at hunting if she wasn't with Chaos and was one of her Hunters.

"Is anyone up for a family reunion, because I'll certainly love to see it at camp Half-Blood? See you later, Olympians."

Her hand was held out as it began forming a black sphere in its palm. She slammed it on the ground as a portal opened up. She looked at her soldiers and nodded towards the portal. The group stiffly went through it, because they were surprised of the bolt incident.

The lone figure looked towards the Olympians, "I am Chao's Assassin. And I've been ordered to inform you of a new threat on the board.

Beware of Order, as He is not on your side.

The group of fallen alphas has been on alkaline.

Chaos soldiers are to your advantage.

As Fallen heroes arrive at campus.

Accept the help for your sake.

Or the twin planets shall fall and fire shall it bake."

Her voice sounded riddles of a long forgotten prophecy. Only Apollo and Athena truly knowing what it meant.

The figure vanished in the shadows of her cloak as she appeared on the hill of Camp Half-Blood. She stood next to Thalia's tree; some campers from camp Jupiter had been at camp as well as Artemis campers. All the people that should be there was present and D.A looked back at her soldiers who watched the scene with awe. They haven't been here for what they thought may have been thousands of years. She looked back as she decided to pop their bubble.

"Did you know that 1,000 chaos years equals to 1 earth year? Your friends and family still is very much alive and in this camp." The group looked at her sharply.

"WHAT?!" they said harshly.

The assassin waved it off calmly.

"You never asked me to know, besides, this was the little surprise I've given you. Enjoy it. It's time to meet the peers of my soldiers that they risked their lives for. Don't take off your hood till it's time. You all will join your friends.

"Bianca will meet with Nico, Zoe and Phoebe their hunters, Luke with his half-siblings and Percy, Silena with Piper McLean, Charles with his half siblings and Leo Valdez, Castor and his brother, Ethan and his cabin with siblings; the whole lot of it. So let's get this over with."

She calmly started to walk down the hill, ignoring her soldiers shocked faces at how she knows of their desires at camp.

Campers looked alarmed at the figure walking towards the dining hall where mostly everyone sat. Some people went to stand but were abruptly pushed into their seats by an invisible force. Stopped chatting and watched at the figure walked to Chiron and whispered something to him. The centaur nodded as she turned back to the campers.

Her voice carried out in the wind with her mouth still closed.

"Hello, campers and visitors on this camp. We have come to aid you in the incoming war. We have come with the ally of Lord Chaos. And my soldiers," she nodded towards the group behind her," has a surprise for you." She raised her hand as sparks appeared between them as she snapped and the group's hoods fell down.

"Enjoy the surprise, campers." She disappeared within the shadows of her cloak and into the shadows of camps grounds.

~~~~~~~~~•

Nico Di Angelo looked shocked at his supposedly 'dead' sister who chose rebirth. He looked at her with wide eyes as he slowly stood up. He and a few others stood up and ran to hug the other people who were supposedly dead. But a few others around Nico looked at him questioningly, he paid them no mind. Bianca and Nico stared at each other before Nico shadow traveled in front of Bianca and tackled her in a hug, Bianca somehow staying standing.

"Bianca ...è che davvero?" He asked brokenly. [Trans: is that really you?]

Bianca returned the hug, looking no older than around 17 as that's when she stopped aging on planet chaos and was immortal.

"Sì, fratellino." she responded as she hugged Nico tightly. [Trans: yes, little brother.]

Nico moved back slightly to look at Bianca's face. He suddenly chuckled under his breath, feeling giddy and a surge of happiness and adoration for his older sister.

"Io sono più alto di te, sorella" he smiled down at her. [Trans: I'm taller than you, sister.]

She moved back and playfully hit his chest, herself feeling happiness and love for her last of family. She grinned and put a hand on his cheek.

"Sei cresciuto." She said fondly. [Trans: you've grown.]

Nico eyes twinkled in adoration and recognition as he grabbed her hand and interlocked their hands pulling her to a table.

"Bianca, Abbiamo una sorellastra da parte di Pluto del padre. Il suo nome è Hazel." he said as he pulled her in front of a table that seated Percy, Annabeth, Jason, Piper, Leo, Frank and Hazel. [Trans: We have a half-sister on Pluto's side of father. Her name is Hazel. ]

His broad grin shocking Hazel, Frank and Some of the others as he smiled. "Guys," he said happily, "this is Bianca, my older sister. Bianca meet Hazel our sister, Hazel meet Bianca our sister on Hades side." Hazel looked at Bianca with a smile and hugged her.

"I've always wanted an older sister!" She cheered.

Bianca hugged her with the same enthusiasm and said, "I've always wanted a younger sister too!"

Nico sat down next to Jason as he watched Bianca with a smile. Jason nudged his shoulder. Nico looked at him as Jason looked at him with a smug smile.

"This is the first I've seen you smile that big, Neeks. Do it more often." He said as Nico glared at him for using that nickname.

"I may be this happy but you can't call me that," he then grew a grin and looked at Bianca with adoration. "Maybe I could get Bianca to stay here after the war, or I could go with her. What do you think?" He looked back at Jason and Piper who shared glances at Percy and Annabeth.

"Nico... I think you should ask Bianca how she got here and stuff before you get ideas." Annabeth said gently.

"Why?" He narrowed his eyes at her.

"Think about it, why would she come here now? She's older than she was when she...passed...and she only looks a year older than you now. Plus, that lady who was here earlier called them her soldiers. They could be part of an army or something like that." She said skeptically.

Nico looked a little deflated before he turned to Bianca again. "Bianca? Who was that lady before?" He asked curiously.

She looked at him and the rest of the people at the table seriously. "We don't really know, no one but Lord Chaos knows who that is. This is the first ever that she actually spoke to anyone and let them see her before. All I know and everyone else in the group is that she's Chao's assassin and she told us to call her D.A." She said quietly.

Percy looked at her alarmed, "She's an as-!" His exclamation was cut off by Annabeth covering his mouth.

"What do you mean this is the first time?" She said seriously.

Bianca looked around cautiously, adding effect. "Rumor has it she only lets people see her beneath her cloak and hear her voice directly is when someone is going to die." She said seriously, "but that could only be a rumor that was made since people only saw glances of her around The Castle of Chaos. And that she never opens her mouth and always wears that cloak and mask."

Annabeth was about to say something when Bianca's groan cut her off. Bianca held her head as she slightly stumbled as well as everyone else in group Alpha. Nico jumped to his feet to help her but she raised a hand to stop him. She snorted and let go of her head.

"Apparently, D.A decided this was the greatest time to create a mind link within everyone in the group. And- dear gods- Luke doesn't know how to keep his thoughts private, Zoe is so going to kill him." She shook her head and Leo looked at her in disbelief.

"So she just created a mind link, just like that? Whoa, that is so cool!" He mused excited.

Bianca stood still for a moment as she looked upon the table and nodded. "She also thinks this is a 'great' time to have the Group Alpha, Clarisse and Chris, the seven of the prophecy, Nico, Thalia Grace and to meet in the big house along with herself. Let's go."

The group stood up and was about to stop walking before Bianca stopped them.

She smirked and took Hazel's and Nico's hands, "I would hold onto someone if I was you." The seven quickly grabbed on the children of the underworld as they shadow-traveled into the big house.

~~~~~~~~~~•

D.A stood on Camp borders as she looked in front of her. A large pile of golden monster dust lay in front of her as she stood on the hill, panting slightly. She had killed the wave of monsters as quickly and as quietly as she could so campers wouldn't be notified. The campers had been switching the shifts as the assassin killed the wave of monsters. She'd know that is was only the beginning and only a warning. She vanished in the shadows of her cloak just as a camper saw the dead monster dust and her vanishing.

She appeared in the big houses ceiling. Using her powers to make herself invisible to the people below her, so then they couldn't see her. They sat in seats around a large table, some standing in on the side of the chairs or siting on the edge of the table. They only jumped up out of their places as D.A made herself visible on the ceiling.

"Holy crap!" Exclaimed a shocked Thalia grace, as she looked up at the assassin.

The pure white orbs twinkled in a taunting amusement as she dropped gracefully on the floor in front of the group and she stood there calmly. Her mask covering most of her face as her mouth was only visible, yet it stayed closed as she spoke.

"It has started. They...," she trailed off as she wiped her shoulder, wiping of the monster dust. "...sent us a failed warning," she faced Bianca with her hands clasped behind her. "Bianca Di Angelo you are my second in command for this mission, Luke Castellan, you will be my third in command for this mission. If anything was to happen to me I wish that Bianca shall take my place as leader of this mission."

Thalia looked at D.A questionably. "Who are you?" She asked a bit rudely causing Jason to elbow her.

The assassin looked at her sharply. "Thalia Grace, daughter of Zeus and Hunter of Artemis. I take no mind of your rudeness as you may call me D.A. As I have many names. That goes for all of you; you shall call me D.A and nothing else."

She then changed the subject, "I've also been ordered to inform you of a new threat to you in the war, particularly why we are aiding you demigods in this war. Order as officially risen and is looking to destroy earth, he can't do it simply as he is weak from his banishment and rise. Although, he is still strong and looking as your enemy in this war. I've also have a warning to tell you,

Beware of Order, as He is not on your side.

The group of fallen alphas has been on alkaline.

Chaos soldiers are to your advantage.

As Fallen heroes arrive at campus.

Accept the help for your sake.

Or the twin planets shall fall and fire shall it bake.

Goodbye Demigods, I shall be there when you need me."

Her voice spoke through the wind as her mouth was closed and she disappeared in the shadows of her cloak.

(I hope you like the chapter)