Well, turns out i didn't need more than one more day to finish the Eternity Death run (Fargo's soul + Calamity).
Was a lot of fun, if you don't mind the early struggles.
Had a few moments where I felt incredibly underpowered (Yharon and DoG especially, they took forever to kill) but felt even better to overcome it all
Anyway, here's the last couple highlights.
Nameless Deity kill
Soul of Eternity created
The final trophy room
Would recommend giving it a go, if you're getting tired of regular calamity or Fargo's.