Backbreaking in casual, and format warping at competitive tables, Hullbreachers asymmetrical resource denial that concurrently generates a massive advantage proved to be too much
In Amethyst/Steel the one foil Jafar is key, then there are just 7 Illusion cards
If youve ever wanted to pit Optimus Prime against a Dalek, getting your hands on some UB is the best way to do it
Another issue players brought up is the fact that errata arent being addressed consistently
Night's Whisper might do much the same for your card advantage situation for the mana and it wouldn't becomes useless as your opponent consumed their hand but that is entirely overlooking the disruption caused by discard
Evergreen mechanics and keywords are common things like trample, indestructible, and vigilance, etc