I know this is the persona 4 forums but I didn't want to put this in the persona 3 FES forum because it dormant for quite some time.
 
Okay, my problem is that I went to the 254th floor of Tartarus and the Monad block did not open up. Is it because I'm playing Persona 3: FES? I'm playing the journey part, not the answer. Any help would be appreciated!

Whenever you make a new topic, it gets bumped to the front page.

If memory serves correctly, that part is unlocked at the very end of the game.

Okay, I realized that they changed the requirements of unlocking Monad in the journey for Persona 3: FES. You have to defeat the reaper and obtain the bloody button from him or beat the game and it will unlock early on in newgameplus. Awesome.