Tony would never consider buying a slave...until Steve sees a friend he thought long dead up for sale. Tony's just here to buy raw materials—and maybe some alcohol—but he can't deny Steve. Besides, that arm is some pretty fascinating tech... He really doesn't know what he's getting himself into. 'It made Tony's teeth hurt. It was kind of adorable. It was just a little disturbing.'

Post-Avengers. Odin, in his infinite wisdom, has decided to go for the poetic justice angle as far as Loki's punishment is concerned. For his attempt to enslave humanity, Loki has his magic and powers bound, and is sent back to Midgard and given over to Tony Stark to be his slave. Tony is none too happy about this arrangement. Eventually Tony/Loki.