Lydia

“The rivalry ends here," Percy said. "I love you, Wise Girl.”
― Rick Riordan, The Blood of Olympus

“I don't feel that way anymore," Nico muttered. "I mean... I gave up on Percy. I was young and impressionable, and I- I don't..."

His voice cracked, and Jason could tell the guy was about to get teary-eyed. Whether Nico had really given up on Percy or not, Jason couldn't imagine what it had been like for Nico all those years, keeping a secret that would've been unthinkable to share in the 1940s, denying who he was, feeling completely alone- even more isolated than other demigods.

"Nico," he said gently, "I've seen a lot of brave things. But what you did? That was maybe the bravest.”
― Rick Riordan, The House of Hades

“Save yourselves!” Percy warned. “It is too late for us!”
Then he gasped and pointed to the spot where Frank was hiding. “Oh, no! Frank is turning into a crazy dolphin!”
Nothing happened.
“I said,” Percy repeated, “Frank is turning into a crazy dolphin!”
Frank stumbled out of nowhere, making a big show of grabbing his throat. “Oh, no,” he said, like he was reading from a teleprompter. “I am turning into a crazy dolphin.”
He began to change, his nose elongating into a snout, his skin becoming sleek and gray. He fell to the deck as a dolphin, his tail thumping against the boards.
The pirate crew disbanded in terror.”
― Rick Riordan, The Mark of Athena

“Jason's fingers itched to draw his sword. He'd met plenty of scary demigods, but he was starting to realize that Nico di Angelo--as pale and gaunt as he looked--might be more than he could handle.”
― Rick Riordan, The House of Hades