I know, I know, old news, and I’ve commented on the end of the Halo 4 Concept Art trailer many times before. But the big red light? Promethean. Has to be.
Also, in the latest Bulletin, it was shown in one question that the Prometheans still aren’t the ‘Ancient Evil’ that we’ve been waiting for so long.
Seems the msot likely, but in the books the Didact was all for preserving life, which doesn’t explain why he wants to destroy Chief now. Frank did comment on a user who had the Didacts symbol as a DP and said ‘All you need to do now is turn it upside down so it is unbound’ Which, in my opinion, may suggest he has gone insane or something along those lines.