[Lawtan]

So MystMist is a Wif-Zombie-Leech?
(Actually don't know Mist's gender, so may be a Wir-Zombie-Leech)

Zombie - brain eating and tired
Leech - has an anasthetic in the bite, so "gentle nibbles"
Wif/Wir - Woman/Man in Old English (Mann meaning "person") used in conjunction with a creature to imply the ability to shapeshift into said creature...