yugioh card polymerization Super [OP14-EN001] Ultimate Rare Oh trading and collectible card game (TCG/CCG) Heavy Polymerization | Yu-Gi-Oh! Wiki

A face down creature has a mana value of 0

It depends on whether you collect for art, play in tournaments, invest for value, or simply want the most cards for your money

Just be careful with the pricing here as it fluctuates based on demand

He puts one loyalty counter on another planeswalker as a passive effect, he can add to his loyalty and make a token that gives you mana to cast planeswalkers, and he can lose three loyalty to draw cards and damage opponents equal to the number of planeswalkers you have

With only one of each legend at your disposal, your opponents will only need to deal with a card once to all but remove it from the game