The check of whether the enchanted creature has three or more +1/+1 counters on it happens as part of the resolution of the attack triggered ability
If you want to get really techy, you could blink it with Cloudshift after the trigger resolves
For example, you can use Sunforger, Silence, and Mistveil Plains to lock an opponent from playing spells (in 1v1 formats), or you can tutor up burn spells and removal for a controlling engine
There's another great benefit to this card, but it comes with a painful drawback, representing The One Ring's corruption
Promo Cards from the Lapras EX Drop event (Promo Pack A Series Vol
Relic of Legends, a simple mana-generating artifact introduced in Dominaria United , is one of them, but its inclusion in the Final Fantasy XIV -themed Commander Deck, Scions & Spellcraft , is given a painful twist