A few minutes ago I was on the first floor of a shop selling some things to Brax. I started drinking some potions to free inventory space, when I drank a radiance potion. Brax suddenly started following me, but allowed me out, only to get swarmed by demons.
Potions of Radiance cast blinding flash when you drink them, which deals damage and some paralysis to all the squares adjacent to you. If you were standing near Brax when you drank it, you hit him, which enraged him and caused him to summon demons.
It's not a bug. When you drink a radiance potion, it does a small attack effect on all adjacent monsters. If you were standing near Brax, the potion did damage to him. Once you injure Brax, he summons demons to protect him. Had you stood around instead of walking away from him, he would have attacked you himself, too. EDIT: Faxed by a Ninja. I mean, Ninja'd by Fax.
