I think it's fun for that: it's hard and that's ok, it's freaking calamity mode! For now, my only little complain could be that, without a good defense, I'm not able to win, while in lesser difficulty modes I can do different strats, like all out attacks and speed and such.
Dunno how you could solve this though. It's tricky balancing a complex game like this.
Also, Haunted is top 2 Synergy for this, for me. Not losing wounds is amazing. Just amazing. Mabek is top aggressive for that too, for me personal.
Sticky figure seems detrimental, but on the long run is amazing.
It's an interesting concept: you can lose the battle, to win the war, in this game. I like it. I did not find this concept in other games like this, where you usually lose the run if you lose a battle.