Magicians Unite (BP03-EN152) - Battle Pack 3: Monster League 1st Edition

Quick-Play Spell Card Activate only while you control 2 or more face-up Attack Position Spellcaster-Type monsters, select 1 of them. That monster's ATK becomes 3000 until the end of this turn. If that monster is destroyed, destroy all other Spellcaster-Type monsters you control.