Thundermon

On Play On Deletion You may return up to 3 Digimon cards with Mamemon in their texts from your trash to the top of the deck. Then, delete 1 of your opponent's Digimon with a play cost of 3 or less. For each one this effect returned, add 1 to this effect's play cost maximum.

Rule Name: Treated as including Mamemon.

Inherited effect

On Deletion De-Digivolve1 1 of your opponent's Digimon.