Mage Tower Referee
From Secrets of Strixhaven set
Mage Tower Referee
Artifact Creature — Construct
2/1
Whenever you cast a multicolored spell, put a +1/+1 counter on this creature.
Rulings
- Mage Tower Referee's ability resolves before the spell that caused it to trigger. It resolves even if that spell is countered or otherwise leaves the stack.