Definitely weakened. Davoth had his power fractured by the Father, and while Doom Slayer inherited a huge chunk of it in the divinity machine, we never see Davoth at full power.from this thread we had Doomslayer as somewhere well above universal https://onelastforum.com/threads/the-security-officer-marathon-vs-doomslayer-doom-eternal.3648/
might be a case for multiversal but Atem said the Davoth he fought was weakened so the full scaling is questionable. Icon of Sin is supposed to be able to merge two universes or something so there's that. Not an expert on Doom so I don't know what relevant resistances he has here vs Ghost Rider's hax