Using it on opponent's creatures is a form of CC. Using it on your own creatures is essentially like delaying them and making them immortal for a turn. Also, the disappearing effect happens before poison, so they avoid poison damage that turn. When they come back, if they fail to disappear, they'll take the damage. The same thing applies to Fire Shield, any Infection effects, and delay effects.
Using it on the opponent is like playing Dusk Shield that only effects one creature.