Blood of Olympus

Leo

Leo gnashed his jaw bitterly. He realized he had just been watching as many brave souls fell. His hands burst into flames on instinct.

Flames raced up his body, engulfing him with heat. He counted to 3, then willed the flames to die down.

Orion clapped, "very good, indeed. I haven't seen a fire user in a long time. Gaea could use a demigod such as you."

Leo stepped back. He had heard this too many times, he actually started to believe it. Gaea thought he was a strong and powerful demigod. He was.

Leo was tired of his friends is better than him. Gaea would give him unlimited power. He would destroy all, with the wave of his hands. He could recreate Hephaestus, as himself.

He tried to shake himself, these thoughts weren't his. But Gaea's force was too powerful. 

He stepped next to Orion, his hands roaring with steady flames, waving back and forth like a snake ready to attack.

Orion clapped, "very wise, indeed, son of Hephaestus!"

Percy gasped, "Leo, how could you?!"

Leo stepped forward, as Orion stepped back. Leo imagined his face cruel and terrible, not the jokish like he used to be. His hands burst into flames.

"You've never treated me well," Leo snarled.

Leo pounced on Percy, the power of Gaea making him stronger and more powerful. There was no need. Percy simply refused to fight his friend. If he did, Leo would be pinned on the floor with a sword to his neck.

Leo's fire didn't harm Percy, probably because of his water protection.

"Percy!" Thalia yelled, she grabbed Leo but recoiled. Her hands were covered in blisters by the time she had wrenched Percy away from Leo's grasp.

Hylla raised her sword for the kill, but Percy tackled her to the ground.

"No! Don't!" he choked, "he's my friend."

Thalia helped them to their feet. 

"Hylla and Thalia, you fight Orion," Percy muttered, "I'll take on McShizzle."

Question:

When did all the 'Team Leo' and 'McShizzle' business start?