Shin Megami Tensei: Persona 4

how do I enter the last floor in Void quest???

I can't seem to enter the "Last Floor" in the Void Quest. I think the last floor was called "Endgame". When I enter the door it seems like the door was sealed with a mysterious power. How do I unlock the last floor??? can anyone help me?

Return to the 7th Chapter (the floor where every T-Junction forced your point of view to change), and explore it fully.

You're supposed to find a room with a mid-boss in it. Defeating the mid-boss will give you the Darkness Orb, which is what you need to open the endgame door.

Like OshareKeiji says, you have kill the mid-boss and it's more easier if you bring chie because her special attack is kick her enemy. Don't kill the almighty hand first just hit it's weakness to hit twice. Just focus to the killing hand. The almighty hand is really annoying but stay focus. Okay...

You can find the mid-boss in upper left of 7th Chapter map, while the upper right of the map leads you to the next floor. After you defeated the mid-boss, check the chest to obtain Orb of Darkness.