The Trickster God and the Infamous Inventor-Thief (слэш)

Tony Stark is one of the galaxy’s finest thieves, and uses his skills as a fear-sale sort of technique; it makes people buy Stark Industries systems to keep them protected, you see. It’s a family space pirate/not-quite-mafia sort of thing; they sell “protection” after all, and anyone who refuses if fair game for Tony’s little hobby of proving how inferior their own systems really are.
A few years ago, Obadiah Stane tried to also make it a war-mongers-for-hire deal, which led to a nasty falling out.
Tony is half-human, but his mother was from an Alfheim community which contained a number of Jotunn refugees from Laufey’s increasingly-unpopular regime. Maria Stark was half-Jotunn, and her marriage to the Midgardian space-pirate brought the rest of the realms of Yggdrasil to Stark Industries’ attention, and inspired Asgard to ally with the Stark family. Tony’s skin doesn’t turn blue, but his “goosebumps” in cold weather look a lot like ice-Jotunn markings, and his eyes turn red when the temperature around him drops to below zero. He lacks ice-powers of his own, but he’s not susceptible to frostbite.
The Three of Nifelheim ask him to go to Jotunnheim and fetch the Casket of Ancient Winters. Loki catches him.