Ancientmermaimon BT18-029

Effect: [On Play] [When Digivolving] Return 1 of your opponent’s level 4 or lower Digimon to the hand. For each of your other Digimon, add 1 to this effect’s level maximum._x000D_
[All Turns] When this Digimon would leave the battle area, you may return to the hand or play 1 level 4 or lower blue Digimon card from this Digimon’s digivolution cards without paying the cost .