union arena demon slayer booster box TCG: Kimetsu No Yaiba 1st Edition [UE05BT] [Rare ] and [Super Rare (SR)] Union Arena TCG Demon Slayer

This follows the same rule as discarding a Helix Fossil to switch your best Pokemon back in

This is important, since you need to build up its power over time

If this card in its owner's possession is destroyed by an opponent's card: Your opponent skips their next Battle Phase

SR Super Rare UR Ultra Rare SE Secret Rare UL Ultimate Rare PS Platinum Secret Rare CR COLLECTOR'S RARE QCSE Quarter Century Secret Rare Egyptian God Slime X WATER Level 10 [ AquaFusionEffect ] ATK 3000 DEF 3000 1 Aqua monster + 1 Level 10 WATER monster Must first be either Fusion Summoned, or Special Summoned from your Extra Deck by Tributing 1 Level 10 Aqua monster with 0 ATK

Given that the Doctor only puts three Time Counters on that card, it would be very easy to time travel a few times to cast almost any spell immediately