Beware, possible spoilers.
- I know they've spent about three thousand years transformed, around the same amount of time Simon was imprisoned. But the thing is both trolls would have had been around to participate in the "Magic of Ten" spell to seal Simon away, so when exactly did Simon manage to turn them into a dragon and tree respectively? This is confusing and annoys me. Unless Simon managed to reach out between realms and shapechange them out of sheer spite.
- Perhaps it was a delayed spell, or right as he was sealed away. A Last Breath Bullet, if you will.