Altair Meme
1) A proper character flaw for your PCs. And not job interview flaws! Real flaws, that makes them not-good people.
Altair's biggest flaw is his problems understanding other people, he doesn't show or embrace emotions making him almost hollow inside, this doesn't help when people are crying or demanding vengence. He just can't figure out why people work like that.
2) A situation in background, or with NPCs, in which your character has behaved badly.
Well. he is a murderer, and a very good one. i would suspect that would be behaving badly.
3) A situation with other PCs in which your character has behaved badly.
Altair lies....a lot. He keeps secrets all the time, and he hasn't lost his touch when it comes to murder.
4) An uncharitable, but entirely true description of your character - how they could be described by someone who knew them very well, but didn't like them at all.
A scary unemotional freak, who is disturbing
5) A redeeming feature about your character.
His best part of him is the fact he can keep a secret, and he will die to protect them. Somethings are not meant to be said and he makse sure that they stay that way