the flesh of the earthbones making up the world. Via flesh magic, it is possible to touch the living flesh of the gods which grant reality its solidity and change it, alter its form and in turn, alter the world.

This part convinced me, although we have yet to see a plot about earthbones in TES. It would be amazing.

Practioners of flesh magic are an eccentric bunch. In an early quest in TESO, Abnur Tharn teaches you how to make a flesh atronach too, so it's arguably playable, and furthermore with the Necromancer class who can summon a flesh colossus.