Moonlight for the fact that both Tony and Loki seem to operate at night more than the day, both saw the Void and the flavors reflect the similarities in their personalities. Masala for Loki's abilities to be calm at times and in your face (spicy) at others. Caramel, with a chocolate accent because these are sweet and smooth (but can be bitter) and Tony has a well-honed gift as a smooth talker as well an addictive love of Scotch.
This tea contains a high level of caffeine | Steep at 212° for 4 minutes.
I've seen Avengers many times and could see the basis for this relationship then. So when I saw that there were no pairing teas, I figured I'd go ahead and make one since I adore the FrostIron ship so much.