Gankoomon [BT13-019] [Versus Royal Knight Booster Pre-Release Cards]

[Blocker] [On Play] [When Digivolving] Without paying the cost, you may play 1 Digimon card with [Sistermon] in its name from your trash or 1 Digimon card with the [Royal Knight] trait from the digivolution cards of your Digimon in the breeding area. This effect can't play [Omnimon] or [Gankoomon].