CMST New Client include the KMST ~ Ulimited New BOSS?

So we know what three of the areas are... the clown, the chicken dude, and the worm thing... but what's the fourth door for?

This creepy lady.

Damian's castle?

Hadriel

Nope. Because you see Damian standing in Root Abyss beneath Sleepywood. Look at the symbol of the doors in Damian's picture.