Granted, this path and the ones involving tokens lean a lot more in the combo direction than the mana acceleration direction, but its definitely worth noting Carnival of Souls capability of being useful outside unreliable 3-4 card loops in these strategies, as it gets a bad rap Im not convinced it fully deserves when reading about its capabilities elsewhere
But knowing what's included in each deck can make that choice clear
What I really enjoy here is the lifelink and deathtouch, like the Vault of the Archangel activation
Vito, Thorn Of The Dusk Rose Vito is already an Orzhov Lifegain staple, but fits ever so nicely into any Edgar Markov deck too, because he is a Vampire Cleric creature type
Kenrith, The Returned King This deck gives access to all colors, which is rare for Group Hug
For example, using the sticker sheet above, you could give Bioluminary deathtouch to make it a costly creature to block