Yawgmoth's Bargain is surprisingly different to Necropotence despite its obvious similarities, it is less onerous on black requirement yet much more mana intensive to get on line
Cards like Isabella Madrigal, Caring Cultivator and Ming Lee, Giant Red Panda both interact with damage counters and healing, but The Madrigal Family only really offers high willpower and ink ramp, which isn't enough to offset the volume of other, more useful cards in this set
Anything you want to accomplish with Rionya can be attempted with Delina, Wild Mage too, but its much harder to pull off, given she makes a tapped and attacking creature, and given that creature will be exiled at the end of combat which will happen as you move to the next combat phase
If they are going to need more than a playset, and the token has potential to be valuable
Both of these cards are at their best against combo decks, but they're still very good versus midrange and control