defensive yugioh deck Yu-Gi-Oh! - Tactics Ultra Rare may be 1st or Unlimited Edition DEFENSE OTK DECK PROFILE!

Self-Assembler: I looked in Gatherer, and there is one previous artifact creature of type Assembly-Worker

Spellbook of Judgment might be one of the most cracked cards ever printed, basically reading that you can add as many spellbook spell cards to your hand as you want along with allowing you to special summon the card with a level equal to the number of spell cards that you activated that turn

(2) Once per opponents turn (Quick Effect): You can remove 3 Spell Counters from your field

While the most expensive Gym Heroes cards tend to focus on iconic Pokemon and trainer combinations, there are also unexpected gems like this Mankey in the expansion