Triggers: Mind-control rape.

-...he was mind-control-raped. When he detonated incoming missiles with a fireball to save his comrades, the blast killed him, but his enemy saved his life and placed him under several mental compulsions -- including one that forced him to sleep with her. He woke up one day completely unaware of this, in bed next to her, and fled immediately -- but the memories returned swiftly and painfully over time.
-He's crushing hard on Celena. On his home world, dragons are incredibly rare, possibly extinct, and are said to be the forerunners of all magic. Then one abruptly showed up at his lab one day -- polite, intelligent, and extremely curious about the magical arts and in general. Is it really surprising?
-He WAS crushing on Vita. But that's settled down now.
-...he's kind of a lonely guy in general. To the point where he's cheerfully attempting experiments that could kill him without much pause for reconsideration, on the basis that it doesn't matter if he dies, only that other people live.
-...Wisdom was his dump stat, not Charisma.