Gideon Olfnir.
Dude's a huge prick the moment you meet him, with his irritated, condescending tone. Then he sends his goon after you and lies about it. "Oh, Ensha? He just got a little ahead of himself. It's all good, you killed him didn't you? No harm, no foul."
Then he tries to stop you from claiming the Elden Throne because... He's jealous? He's lost his fucking mind over the fact you, a lowly Tarnished, managed to get that far? I really don't know. It's a bit confusing, well beyond other weird shit in a Fromsoft game, and part of it could just be how this game in particular was a collaberative effort with GRRM and there is likely a huge difference in what Martin wrote for the backstory, and how Miyazaki "corrupted" it.
I really don't understand the dude. Maybe there's an item description that would give some context... 🤔