u/Death_magnetic1209

So just got the game, have already played eternal atleast 5 times through, but i was curious as to how ultra nightmare works in this game, as it says I need to heal with life sigils? Why is it that way and was it always like that? Also wondering how hard it is compared to eternal as I want to do it but just doing hurt me plenty on my first playthrough im still getting shredded. Also open to any tips and tricks to help get better. I kinda suck at doom🥹