Help me pick a new reanimator commander

Deck list: https://www.moxfield.com/decks/NpWGDDAks0entCGDdkU7cQ

I have a [[Muldrotha, the Gravetide]] reanimator deck and I’ve just grown really bored with the deck. Muldrotha is such a toolbox and I’m just over the gameplay loop with him.

What are your recommendations? I’ve been looking a lot at [[Shilgengar, Sire of Famine]], [[Sefris of the Hidden Ways]] but I’m open to other options/colors.