The last question was hard. The main guess was Steel, but don't worry, I though it was too until I looked it up. According to the three different websites I looked at, Nyssa's last name is Barrera.

Disclaimer:

"Leo, where are we?"

"Well, Nico, apparently, some chicken named Myra109 has kidnapped us. I suggest you just do what she says; she's a little... off pudding.

"Thank you, Leo. Nico?"

"No!"

"I'll deal with you later. Leo?"

"Myra109 owns nothing, not even us!"

"I shall soon change that... JK."

The Chimera lunged right off the bat and Percy drew his blade, bit his hands were shaking pretty badly. Still, Leo was glad to know that Percy was brave enough to fight this thing and not curl into a ball and wait for death (he'd seen that happen before when the demigods were just too tired of fighting to go on).

Leo dove to the right, rolling next to the mortals, and holding his dagger out to the monster. He caught Percy's eye and gave him a look that said, 'Distract it while I get the mortals out of here.'

Percy sighed, like 'easier said than done' before rolling to avoid the Chimera's fire breath. He continued to run around the Arch like a little kid hopped up onto much sugar while the Chimera raged and tried to kill him in three ways, sometimes all at once.

In the future, Leo would've congratulated him on his idea or laughed at the mere mental image, but right now, he had some traumatized mortals to deal with.

He faced the four people and got ready to explain as hurriedly as he could what the hell was going on here.

"Boy, you better tell me what the hell that thing is," the security guard growled, but his eyes displayed fear.

Leo took a deep breath before launching into the dreaded explanation. "Alright, that is an experimental machine. The government has been working on robots like these to fight terrorists and possibly violent criminals, as well as to be used during war. But something went wrong and the machines went haywire. The government hired several 'monster hunters' as I call them to catch these creatures and get them under control. Those hunters had numerous children and the children are raised to fight the creatures because the creatures were programmed by the monster Hunters and trained to recognize them and only them. That way if a terrorist gets a hold of one, the terrorist cannot use it and the machine goes into lock down. Get it?"

The mortals slowly nodded, but Leo could tell their confusion was still there.

"How do we defeat it?" The mortal father demanded, dragging his wife and child closer to him.

"You can't," Leo answered, "but my friend and I can. All I need you to do is stay back and as soon as those elevators ding open, get the hell out here. Got it?"

Someone tugging on his shirt caused Leo to look down and he saw the boy looking up at him in curiosity.

The boy looked familiar, maybe around four with brown eyes and black hair hanging in his face while he tried to blow it away in irritation. His face was pale but his eyes shone with a bright innocence that Leo could only wish he still possessed.

"Are you gonna defeat the monster?" He wondered.

Leo smiled. "Yeah, kiddo. What's your name?"

"Harley," the boy said.

Leo froze. It couldn't be...

But it was. He could see his little brother in those big brown eyes that were innocent but too calculating for a child of four years old.

"Well, Harley, I'm Leo. And I'm gonna defeat that monster and make sure you're safe."

"You sound like a hero," the boy chirped.

Leo laughed. "I'm no hero. I just do what's necessary; maybe some day you'll understand what I mean, just hopefully not under the same circumstances." He chuckled, nervously, glancing at the Chimera. "But you gotta trust me. Stay with your mom and dad and do exactly what I said. Okay, Harley?"

"Okay, Leo," Harley agreed with an almost hilariously serious nod.

"Good."

"SHIT!" Percy's shout echoed in the Arch and Leo looked up to see that Percy had gotten hit by the Chimera's poison. He was now clutching his leg and trying to stem the flow of blood.

"Percy!" Leo shouted.

He was racing across the battlefield, but he knew he'd never get there in time. He quite literally tripped over Piper's dead body in his haste, but that only made him run faster. He would not lose another friend.

Percy and Annabeth were begging to live, and that hurt like hell. The demigods that had survived Tartarus were pleading for life, and Leo wondered how long it would take for that begging to live would turn to pleading for death.

That weird giant with the milky eyes raised his cleaver and brought it down on the demigods.

Leo could hear their dying screams from across the battlefield, and then, as one, their screams ceased and it was silent.

Dead silent.

Leo shook himself out of the flashback (or was it flashforwards?) and caught Percy's eye. He remembered the story future Percy had told him, and although he wasn't exactly comfortable knowing that Percy was falling at least six hundred feet, he knew there was no other choice.

"Percy, jump!" He screamed. "The Mississippi River is below us! It'll heal you!"

Leo figured he must sound crazy to the mortals and Harley, and what happened next probably scared them even more.

Percy had trusted him (which warmed Leo's heart, knowing that the son of Poseidon trusted him in this time line, unlike the previous one). He leaned back and went splashing into the water below.

"Damn it!" Echidna cursed. "You lost me my prey!"

Leo stared at her. "Prey? I don't think Percy would taste too good; I mean, he'd probably taste really salty, you know?"

Leo heard Harley giggle, and almost smiled at his little brother's laugh, but he kept his gaze focused on Echidna.

"Zeus has prevented me from killing you yet, but don't worry, child, you have made an enemy of all monsters. You will never be safe."

She vanished, along with the Chimera, but three Manicores had taken her place.

Leo had fought plenty of Manticores in his life times, but that did not make them any easier to defeat. He heard the elevators ding open and heard the footsteps of the others rushing for the doors. Honestly, he would've joined them, but he was afraid that the Manticores would follow him and terrorize the others. Therefore, he stayed where he was.

Slash! Dice! Slice! Cut! Leo's blade was a blur as he chopped at the three monsters, occasionally having to light himself on fire or slice a dagger out of the air.

But he was quickly tiring, his movements becoming sluggish and slow. A dagger skimmed his shoulder and pain began to pulse through his arm.

He was slapped in the face with a tail and sent soaring, nearly avoiding the gaping hole in the wall that the Chimera had made. Glass bit into his skin and he could feel blood welling up on his cheek.

"You will not win, little demigod!" One Manticore cackled.

Seriously? Monsters need to get some new lines. Leo thought about saying that, but as soon as he opened his mouth, smoke from the numerous patches of fire across the observation deck flowed into his mouth. He may be immune to fire, but smoke was another story. He began to hack and cough until he was sure his lungs would collapse.

Leo sat up and looked at the approaching Manticores through bleary eyes. He knew what could defeat them; he'd done it once in the future, but it had nearly killed him. It wasn't nearly as bad as when he fought all of the Giants at once though, so it was worth a shot.

He thought of his mother, of Nico, the seven, of Harley, of all the people that he had grieved and he also thought of Ms. Teresa, Blake Magista, Cruella Reveen, Gaea, and so many others that had angered him or taken something from him. And he exploded.

Black fire streamed off his body, flowing forwards until it stabbed through the hearts of the monsters, burning them from the inside out. They burst into dust.

Leo was exhausted, but he staggered to his feet and raced for the elevator, hopping in and making a break for it before any security guard could get a good look at him or grab him.

He continued running, scouting the crowd for Percy, Annabeth, and Grover, but didn't see them, so he did the logical thing. He kept running until he reached the train station and prayed that they were safe in the compartment.

And they were. Other than looking anxious, dejected, and tired, they were fine.

Leo smirked and slid open the door. "What's with all the long faces?"

"LEO!" They cheered, looking so relieved it kind of scared him.

They enveloped him in a group hug and Leo smiled. He hadn't gotten a hug since... Jason died? And then Piper screamed as she sobbed into his shirt. That wasn't a good memory.

As a child he may have shoved them away or made a joke, but he knew better now.

Moments like these were to be cherished.

There will be more on Harley later (like why he has two parents and why he was a year round camper). Also, there will be more on that emotional fire, as I call it, later; it will actually play a major part in the series later in.

Finally, that explanation of the monsters to the mortals is based off of NBrokenShacklesN's, but their's is a lot more complicated and thought out than mine. Mine was just something Leo thought of on the spot from watching too many spy movies.

Which giant captured Piper's dad in the Lost Hero? (Name, please, not who their the anti of)