Percy had fallen into Tartarus by himself, he threw you back up but sacrificed himself in the process

You tried to jump in after him but Nico held you back. Now you were on the Argo II keeping an eye on the ship while the others were at the doors of death.

The hours flew by painfully slowly, but you heard commotion of people it was your friends, you immediately looked for Percy when you saw him he looked.. different

His eyes seemed darker and overall he gave a more dark evil vibe