Umbreon (17/17) (Star) [Celebrations: 25th Anniversary - Classic Collection] Duel Academy Box You can only use this

You can only use this effect of "Mermail Abyssteus" once per turn

you can take control of That monster up to the End Phase

Set: Ancient Prophecy Card type: Synchro/Effect Monster Rarity: Ultimate Rare Attack: 3100 Defense: 2600 1 Tuner Monster + 1 or more EARTH Monsters

Set: Power of the Duelist Card type: Effect Monster Rarity: Ultimate Rare Attack: 600 Defense: 800 Once per turn

but return it to the hand during the End Phase

Umbreon (17/17) (Star) [Celebrations: 25th Anniversary - Classic Collection] Duel Academy Box You can only use thisSet: Celebrations: 25th Anniversary Classic Collection Type: Darkness Rarity: Ultra Rare Retreat cost: Colorless