Wonder why you said it like that.
So after much deliberation I’ve decided that Celain’s ability will be the power to control portals. The catch is that he can’t use them to travel to different worlds and achieve the control he wants to; he can only warp within his current world. Eventual transportation to a new dimension is still something he has to deal with, so he still has a reason not to develop emotions.
There, no second powers. Can’t believe I didn’t think of this before; well, Mango brought it up privately, but at the time I thought having control over portals meant having control over his power as a whole, thereby defeating the purpose of the character, so I wrote it off. Not necessarily though. Compromise achieved