Massacre Wurm is incredibly strong, as it drains 2 life from each opponent whenever one of their creatures dies
It all revolves around his main abilities: turning artifacts into Food and, well, eating them
They have simple to understand card mechanics and form the base of any deck
Vanadiel Adventurers Laboratory Maniac at uncommon means you can actually get multiples sometimes, so there could be self-mill decks that try to win with this, Town Greeter, and Fight On
His ability lets you turn dead cards into combat strength, and this also makes him really hard to block/remove
2020-01-24 Colorless and generic mana symbols (, , , , , and so on) in mana costs of permanents you control don't count toward your devotion to any color