Ulalek, Fused Atrocity

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

If a card loses devoid, it will still be colorless. This is because effects that change an object's color (like the one created by devoid) are considered before the object loses devoid.

Resolving copies of permanent spells become tokens as they enter the battlefield. These tokens are not considered "created" when this happens.

The copies are created on the stack, so they're not "cast" or "activated." Creating the copies won't cause abilities that trigger when a player casts a spell or activates an ability to trigger. Abilities of copied spells that say "When you cast [this spell]" won't trigger.

Ulalek must be on the battlefield in order for its triggered ability to trigger. Casting Ulalek itself won't cause that ability to trigger.

Each copy will have the same targets as the spell or ability it's copying unless you choose new ones. You may change any number of the targets, including all of them or none of them. If the spell is a permanent spell with targets, such as an Aura, you may also choose a new target for that spell. The new targets must be legal. If, for any target, you can't choose a new legal target, then it remains unchanged (even if the current target is illegal).