Board Thread:Fun and Games/@comment-25322628-20160912191347/@comment-27929601-20161007124121

I don't think the Ego Stone/Gem would be used in the MCU, because even to various comicbook readers is unknown, but who knows, maybe they are thinking about it.

That is a better plan about controling Loki because he is afterall the "god of lies", but we probably haven't seen the whole plan, which I assume would be revealed in Infinity War.