It is recorded off the Xbox One X DVR (4k) The Master Key Achievement in Katana ZERO
You will need to progress the level normaly till you reach a room before the balcony in which 2 enemies are inside.
Before you open the door you need to pick up the bust
) & then wait (easier
) for them to bunch up then open the door & kill them both.
you killed them both first just go back and pick up the bust then proceed.
You will need to slow down time (
) then hurl the bust at him (
) I held down
just to be sure.
After just go to him and once you pick up the key (
) the achievement will unlock.
a bonus achievement
is also here What a bad idea
achievement in Katana ZERO
just jump off the balcony and you get it. (resets the level
All of these levels can be replayed via the tapes in Main Menu -- Continue -- Tape #2 Hotel B--+---(+ this one)--E
I know i know the pop up sign of the achievement didn't unlock but again via Xbox dvr, Enjoy.