[Epyon MX]

Spoilers:

He does want to share it with the world. That's why as soon as he gets back he tells Obadiah to start work on the Ark Reactor and abandon weapons development. But that one in his chest, one that small, is for him and really for Iron Man alone. I gathered he was intending to develop better ones than the big one to give to the world. Of course, Obadiah rightly points out that the thing isn't cost effective in any way shape or form, so *shrug*.