As I’ve only discovered just this past week (from playing many Variax Control mirrors), Duelyst’s current “fatigue” system deals a flat 2 damage per every card overdrawn (e.g. 1st = 2 damage, 5th = 2 damage, 19th = 2 damage).
In contrast, Hearthstone’s “fatigue” system deals a scaling amount of damage per each card overdrawn (e.g. 1st = 1 damage, 5th = 5 damage, 19th = 19 damage, etc).
Now I would argue that Hearthstone’s fatigue system is phenomenally supportive of strategic play, as it adds a deeper and more skillful layer of resource management to heavy control mirrors. As such, I don’t see any downside to implementing said system in Duelyst, as the vast majority of the current meta (aggro/tempo) will never approach fatigue, and therefore a change would have no impact on the vast majority of players.
I understand that this would be a relatively small, “quality-of-life” improvement then, but I (and I hope others) would greatly appreciate an additional layer of depth. I’d even take this first over the Shadow Creep counter. 