I recal the Iifa tree being a big part of the soul gathering, as well as the Invincible, though it's really not to relevent to the discussion. :P
And I thought he had seen trance before, I figured that whole scene was him getting the Idea of just how to release a trance himself, rather then him stumbling across it, much like Kefka with the Triad.
Though yeah, I guess one could call that stumbling if one desires, it's all semantics anyway. :P