union deck yugioh Complete Custom for Yu-Gi-Oh! Heroes' Union - Yugipedia

Straightforward and elegant design

The drawback of also providing an opponent with three cards will feel pretty terrible if your game is down to two players, but the rest of the time, youll often be in a position where those cards could be granted for favors (Dont attack me for the next two turns!) or in order to help another weaker player take down the table threat

A huge prize is a serialized card with a limited number of printings

The Halo Foil version can reach $90 and above in good condition, so keep an eye out if youre still opening packs

During your Main Phase, if your opponent controls a monster(s) with 0 ATK: You can add Reptile monsters with different names from your Deck to your hand, up to the number of monsters your opponent controls with 0 ATK, also, you cannot Special Summon monsters from the Extra Deck for the rest of this turn, except Reptile monsters