[On Play] By placing this Digimon under 1 of your Digimon with [Legend-Arms] or [Xros Heart] in its traits as its bottom digivolution card, [De-Digivolve 1] of your opponent's Digimon. (Trash 1 card from the top of 1 of your opponent's Digimon. Stop trashing when you would trash a level 3 card or the Digimon's last card.)