Ultimate Flare [BT5-105] [Battle of Omni]

[Main] Trigger [De-Digivolve 3] on 1 of your opponent's Digimon. (Trash up to 3 cards from the top of one of your opponent's Digimon. If it has no digivolution cards, or becomes a level 3 Digimon, you can't trash any more cards.) Then, delete all of your opponent's Digimon with play cost of 3 or less.