Lifelink
Whenever an Aura you control becomes attached to a nonland permanent an opponent controls with mana value less than or equal to that Aura's mana value, gain control of that permanent for as long as that Aura is attached to it.
If the mana cost of a permanent includes {X}, X is 0 for the purpose of determining its mana value.
12 Apr 2024
If the Aura you control becomes unattached from a nonland permanent (most likely because the Aura left the battlefield) before Eriette’s triggered ability resolves, you won’t gain control of that nonland permanent at all.