Godsend in edh

[Chargingswadger]

In edh if I exile their commander with {godsend} and then it ors back to the command zone, dies godsend last ability prevent then from casting it?

[Remillo]

In edh if I exile their commander with {godsend} and then it ors back to the command zone, dies godsend last ability prevent then from casting it?

Nope.  If it goes back to the command zone, it's no longer in Exile.  Since Godsend looks for card linked to it that are in Exile, and the commander isn't there, nothing is preventing it from being cast.  The only way you could get that to work is to exile another copy of that commander that's in the 99 of someone else's deck, which is pretty awkward.  It also means that you can use cards like {Pull from Eternity} and {Riftsweeper} to actually nullify Godsend's ability by nabbing cards from Exile.