If you find them someplace for $40 each, thats a pretty easy buy
Bartolome and Yahenni both slot nicely into this build, as well as the traditional Altar of Dementia/Ashnods Altar
Myrkul, Lord of Bones (Check it out here) was built as the leader of a Midrange and Constellation deck that ran a bunch of dorks with ETB abilities for value (like Liliana's Specter and Archon of Cruelty), sacrificed them for value (High Market and Dockside Chef), netted a return as an enchantment to trigger another ETB for it and constellation dorks (like Underworld Coinsmith and Eidolon of Blossoms) and then added in some ramp, answers, card flow, and called it a deck
Whenever you discard a nonland card, you may cast it from your graveyard
It was also one of the defenses against Necropotence decks, since you could shrug off discard and if they played Necropotence they wouldn't get the Mine card
The best way to build around this red creature is to pack your deck full of devils and any and all red cards that can cause chaotic game states, which there are honestly a lot of