Ive read Avengers: A Deal with the Devil by IBegToDreamAndDiffer
(https://archiveofourown.org/works/1163358?show_comments=true&view_full_work=false#comment_128293551 ) which also has dark/evil Tony. Im not a very big fan of it, but this is the only fic with evil Tony that I love. Its actually amazing and has both magic and immortal Tony in it.
I hope someone can give me some recs! I need more magic Tony in my life. Thanks! :)