[LumenPlacidum]

Regen with mistform is even better than usual, so I'd definitely go for some regen. I would definitely have some reinvigoration to counter the casting fatigue.

In a SP game, I think you should use the hydra skin armor and messenger boots. If it were a MP game, i would sacrifice the extra reinvig for more MR and go with the rainbow armor plus ring of regen. Of course, the air queen cost a fair number of gems to begin with, so I'd probably spend even more gems on her. I think I's use the rainbow armor, ring of regen, and some of those stone boots for extra protection against hits bypassing mistform. It can mean the difference between keeping the thug (and she runs away) or having it killed on a bad turn.