According to Schmoes Know , Mantis is set to make an appearance in Avengers: Age of Ultron! The character has a lengthy and somewhat confusing history, but fought alongside Earth's Mightiest Heroes against both Thanos and Ultron. She has ties to many of the characters being introduced in this movie in fact, as Mantis even had romantic feelings towards The Vision for a time! Her history gets a little complicated (she actually appeared in DC Comics titles as "Willow" for a time), but Mantis has in recent years become a cornerstone of the cosmic side of the Marvel Universe.The site claims that their source told them:Fair enough, but they shed no light on what her role in the movie will be or who might be playing her. As a result, it's best to take this with a pinch of salt for the time being, but do we now know the identity of the woman in that cave in the trailer? As always, be sure to share your thoughts and theories in the usual place...