Lotus-Eye Mystics

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, return target enchantment card from your graveyard to your hand.

Pioneer Masters

The List

Ultimate Masters

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Lotus-Eye Mystics enters the battlefield, return target enchantment card from your graveyard to your hand.

Fate Reforged

Prowess goes on the stack on top of the spell that caused it to trigger. It will resolve before that spell.

Prowess triggers only once for any spell, even if that spell has multiple types.

Any spell you cast that doesn’t have the type creature will cause prowess to trigger. If a spell has multiple types, and one of those types is creature (such as an artifact creature), casting it won’t cause prowess to trigger. Playing a land also won’t cause prowess to trigger.

Once it triggers, prowess isn’t connected to the spell that caused it to trigger. If that spell is countered, prowess will still resolve.