Gigantic Thundercross (MP24-EN329) [25th Anniversary Tin: Dueling Mirrors]

Target a number of monsters on the field and/or in the GYs, equal to the difference between your banished cards and your opponent's; banish them, then your opponent can Special Summon 1 monster from their Deck. You can only activate 1 "Gigantic Thundercross" per turn.