Path of Annihilation

Devoid doesn't affect the color identity of the card for the purposes of the Commander variant. For example, while Abstruse Appropriation is colorless because it has devoid, its color identity is still white and black, and it can't be included in a Commander deck where the commander's color identity doesn't include both white and black.

Path of Annihilation's last ability resolves before the spell that causes it to trigger. The ability will resolve even if that spell is countered or otherwise leaves the stack.

Devoid works in all zones, not just on the battlefield.