Creatures native to a plane other than the prime material plane can only be killed permanently on the plane of their origin. For example, if a creature from the outer planes is summoned to the material plane and slain there it will be reborn at the place of its origin a few days later. This rule applies to gods as well. A god who is defeated outside their home plane is banished to their home plane. A god killed on their home plane is permanently killed. The one exception to this rule is the residents of the Feywild. Fey killed on another plane are reborn in the feywild, however Fey killed in the feywild are also reborn there.