Powerful mages, often necromancers, know the ritual to use flesh and the essence of Daedra to form a Flesh Atronach bound to their will.
To do so requires 6 hours of work correctly filling a circle with Osseous Marrow, Dermis Membrane, Essence of Breath and Blood Liqueur. These special ingredients can rarely be bought, and must instead be found. They can be harvested from slain Daedra by making a -20 Alchemy test limited by Lore, though a single Daedra can only usually supply one of these at a time.
Once the ingredients are harvested and placed in the circle, as well as the 6 hours have passed, make a +0 Conjuration or Necromancy test. On a success, the Flesh Atronach raises from the circle with the Bound trait. The atronach has no weaponry when raised, so you must affix it yourself. Your GM should handle how you may find or create the atronach’s weaponry, either by finding a smith to do it or something else.
If the character wishes to create a Hulking Flesh Atronach it instead requires two of each ingredient but follows the same ritual process.