reworked cas' backstory + changed his model again :3c details below!!
as a result of being born after mordremoth died, when the pale tree was still very unwell, he awoke with an extremely heightened sense of empathy; although all sylvari can feel each others' feelings to a degree, to cassien it was all-encompassing and unbearable, leaving him unable to tell which feelings belonged to him.
desperate for anything that could help, he was groomed into joining the nightmare court, where he was set up as a squire under a knight and suffered abuse at his, and the other courtiers', hands. the knight he served under had a fierce rivalry with another in the court, and cassien was more often than not caught up in between the two of them.
before the start of PoF, the commander is back in mainland tyria. the rival knight, seeking to get back at his enemy, gives cas a cruel ultimatum; kill the commander, or suffer. cassien can't say no, even though he knows it'll be impossible. still, it's a better alternative. so he seeks out atlaki, sneaking onboard the airship that's set for elona...only to become an unwilling stowaway when the ship sets off with him trapped on board.
he's quickly discovered but lies about his intentions, and is allowed to stay. he grows close to the commander, first as a ruse to get close enough to kill him, but later developing a genuine fondness for him - as much as he denies it. he's bewildered by the kindness atlaki shows him, and for the first time in his life, away from so many other sylvari, he starts to feel better.
the threats of the court, the influence of nightmare, and a lifetime of abuse hang over his head, but slowly, he comes to realize he doesn't want to kill atlaki. it's something he fights against for a long time, even up to the point when atlaki finds out his true intentions. but for the first time, he can do what he wants, even if that means going against everything he's ever been told.
when you’re, apparently, the first one at that place who can’t work with the laptops bc they make you dizzy and headachy, it really makes you feel. something. like wow, i really am way more fucked up than everyone else, who are all normal and unproblematic