Name that Netflix movie? (Historical Asian)?

So trying to remember this movie I saw a couple years back on Netflix.

It was about a young Asian guy who fell in love with this girl. She got drafted to go to the palace and he was drafted for the army or palace guard. I remember him being forcibly castrated on the screen (ew?!) And they had to meet in secret.

Cue in bad guy who wants the leading lady for himself, a weak Emperor who just wants to party and general shenanigans.

The ending was her riding off a cliff with her lover's lifeless body rather than be the bad guy's bride and or concubine.