Guardian is the worst, hands down, and I don't see anyone arguing for a worse class. How often do you see Wall-Knight, Citron, or Spudow?
This week Wall Knight is one of the featured Event class and you still don't see it all that much.
"For wall knight, you have this very annoying cornucopia deck."
The only way Wall Knight is good is with 4 Legendaries...this is a pretty good way to define an awful class.
Wall Knight signature power is incredibly situationally useful, and is probably the worst starting-hand Super Power in the game. You can spend your early mana instead of playing to throw it away to deck cycle. Hooray?
His powers are the worst collection of tricks in the game AFAICT. With many Super Powers, you can win a game. With Wall Knight, you can die next turn instead of this turn.
I can win with Wall Knight in Casual sometimes. Ranked is laughable.
Mirror Nut is fine but (esp for Wall Knight) is all or nothing. If that one trick pony doesn't work, isn't drawn, or is countered, the deck falls apart.
Almost the entire Mirror Nut deck can be destroyed with one card (Weed Spray), which any Hearty zombie should have four of.
I laugh when I see Spudow on the other side of the lawn. That's not a good sign that you've properly balanced a class.