Astarion, the Decadent This 6-mana 4/4 with deathtouch and lifelink lets you choose Friends or Feed at your end step, which either doubles the life lost by a specified unlucky opponent or doubles your total lifegain that turn
Everyone has seen these cards before and they get stale after the first or second time
Avoid attics, basements, and areas with temperature fluctuations
Whenever chaos ensues, creatures cant attack you until a player planeswalks
Beyond that, I'm not sure exactly what deck wants this, because I think it's a bit much for what something like Kuldotha Red would be interested in, but the flexibility is worthwhile alone
Newer titles have moved away from the paradigm of the heroes of light collecting the scattered crystals in favor of broader, more convoluted plot-lines, but most games in the series still have a crystalline element somewhere