Percy Jackson. The name rippled through the camp like an incantation. No matter how tired or injured a warrior was, they brightened and stood a little straighter when he strolled past.
He was the only one without a single scar, despite the fact he was always in the very center of the fighting - or, occasionally, an entire fighting force in and of himself. Everyone had seen weapons bounce off him. Everyone whispered about why. He'd bathed in the Styx, he'd been blessed by Ares, Hecate herself had fallen in love with him and given him an enchanted coin. Even the wildest theory was held as plausible. It was, after all, Percy Jackson. They said the only reason he wore armor was because he thought if they had to cart it around all day, he should too. They said he was unkillable. Invulnerable. Immortal.
Whatever it was, it radiated off him in a powerful aura. There wasn't a drop of water that didn't reach for him as he passed. There wasn't a warrior that didn't gravitate towards him, in battle, at the campfire, in the command tent. He was the sun they orbited, desperate for the life giving deadliness that protected them all. Desperate for some of that confidence to rub off and ease their terror filled sleep. Desperate for that twinkling humor that even the war hadn't completely driven from his eyes.
It might have been terrifying, if you thought of it, to realize that the same man - and he was a man now - who comforted the terrified eight year old they found in the woods, who added the perfect dash of "crazy" to the Athena cabin's brilliant plans, who could rally them through every death and setback and loss, who kissed Annabeth when he thought no one was looking - he was the same man with that deadly fury in his eyes as he drowned their enemies where they stood. He was the same man who sent countless monsters screaming to Tartarus with every sweep of his sword - and once had followed them there and lived to tell the tale.
The Romans sent spies to their camp. None of them ever reported back. The Romans assumed they'd all been caught.
The Romans were wrong. Very few of the spies had ever been caught, mainly because they spent one day in the Greek camp and decided they absolutely, positively, did not want to do anything that might upset the Greek general. What started as terror was quickly roused to loyalty until they would have happily followed him back into Tartarus if he had a fancy to go.