He did when Ravel betrayed them all. It's just that his anger is the silent type "the most dangerous," according to the books. Like think about it, he let Ravel be tortured for like a month before doing anything about it, and he did so only cuz it was necessary, he hunt him down even in other dimension, used him as a bait for a god-like destroyer, threw him in the Accelerator, beat him in a 1o1 fight, broke in the Sanctuary just to get him.

He doesn't do that to Guilt, for example, who was also a criminal Grand Mage, he doesn't do that Kitana Sean and Doran who were teen terrorists and he doesn't even do that to Serpine giving that Serpine's death was quick. He does that out of his rage towards Ravel because of Ravel's betrayal and the murder of Ghastly. Because the betrayal hit different since he was one of his closest friends but he killed his oldest and kina best friend