Kaya's Ghostform instead of Unholy Identure, saves some mana and slighty better protection
or
Curator's Ward for protection and a little bit of card draw
and a little card, often forgotten, for Muldrotha:
Claws of GixSacrife any permanent when you need - just for example to play any planeswalker each turn by sacrifing them bevor, so you can just keep going with the same one
Pernicious Deed is similiar to Nev's Disk, but you have a bit more control what it hits and it's a good repeatable boardwhipe agains token decks
Lotus Petal for Ramp / Fixing is for Muldrotha just one free mana per turn if you can't / don't need to play a other artifact
Edit:
Deadbridge Chant is also nice mill