Iskandar's Will save bonus is higher than the listed DC's, and he cannot auto-fail on a 1, so he automatically succeeds against the listed DC's unless they are higher for him for some reason. I went ahead and rolled anyway, just in case:
Refusal: 26
Fear: 31
Insanity: 36
Death: 37Dyson's probably still our best bet at getting past the door, as Iskandar can pretty much only try to slice it to ribbons. If there's a crack, he could probably slip through it in sand form, but then he might be stuck alone in a bad spot. :O