About this image

Xanadu used to have a different face but then I saw Corus head from Hearts' Heads and went "yep, that's my man right there".

He's a paladin of vengeance and my headcanon is that he swore an oath right when Orin betrayed him. Obviously, he meant it more as "bitch I'll kill you twice".  But some random god heard him, took pity on him and decided to interpret his deranged ramblings as an oath. And then later his desire to avenge himself morphed into "yay vengeance for all" because he doesn't remember what happened to him, he just woke up in shitty mood and with paladin powers.
His deity isn't Bhaal though (not anymore!), that's for sure. I don't think Bhaal would accept an oath from a "weakling" who was being lobotomized at that moment lol

And the idea with his appearance was to reflect some of his duality - you know, being a Bhaalspawn and an evil-smiting paladin all at once - on his face. Red glowing eye being an obvious thing of course lol but the burn scar is meant to look like half of his face is constantly bathed in shadow