Can you use the Feral Variant from SCAG on the variants in Mordenkainen?

Why don’t the Cadaver Collector, Eladrin, Skull Lord, Sorrowsworn, Steel Predator… have save proficiencies?

Leviathan damage

Fascinated by the D&D multiverse?

Mordenkainen’s Tome of Foes – Official ERRATA

Mordenkainen’s Tome of Foes ERRATA 2020

Shadar Kai die and are resurrected in the Shadowfell by the Raven Queen. Does this apply to Shadar Kai PC’s?