I think the most difficult and annoying part of doom tower for me is Mortu.  I am not sure why Block Revive is necessary to stick through Waves, but it is very annoying to fight a 15 minute battle in hard DT just to fail because your short a hero because Peril which is almost unavoidable unless you can keep them stunned or provoked, which doesn't seem possible with my line up... not sure if its just me, but this is very frustrating.  90% of my doom tower progression in hard each reset is shut down by Mortu, generally not the bosses.

Would not be the biggest issue with you could revive your champions in subsequent rounds, but losing a champ to a nearly unavoidable 1 shot mechanic and trying to clear 2 more waves in rounds 2 and 3 is almost impossible for me.  Sometimes i get through a stage with i get super lucky stun procs, but it generally takes me several attempts.   This rotation, i cannot for life of me get past stage 86.

There is no way im the only one really struggling with this.

Last line up i used was Fu Shan, Scel, MM, Vermin, and Soulless, eventually one of them loses CC and starts going on a rampage.