Not sure why. Discovered a Silver Serpent while using the newer Whizbang with a morphing card turned into Flint Firearm. Couldn’t play Silver Serpent either that turn or the next, even with the necessary mana to play it.
This morphing card(mirage)? Or the wizbang deck of all morphing cards; Either way all morphing cards most likely use the same coding so probably tied to this bug