Alright, for you people who think that the Didact is not dead then obviously you don't pay attention. Let me break it down to ya:
1.) the Didact killed those people on Earth (obviously New Phoenix, if you watched the Spartan Ops episode) with the Composer. Not because he survived a fall to Earth.
2.) Master Chief put A Pulse Grenade in his chest, so obviously he's dead.
3.) if he didn't die by that he would have died falling into the Composer, or if he didn't fall into the Composer (which he did) he would have did on his way to Earth.
4.) CORTANA IS NOT DEAD! The whole story has been about her and Master Chief. So, they will either make Cortana again using remnants found of her old processor and Dr. Halsey brain power.
5.) Spartan Ops will probably lead into Halo 5. No complaining about bad story telling or that Master Chief is in the Spartan Ops. That's just stupid.
6.) Halo 5 will be absolutely epic about everything. About saving Cortana, about the Chief, a new antagonist, and any other concerns you may have.
NERD OUT!
OK they didnt show his face. They showed them removing his armor but no face-time for the Chief.
