Colourful Bone (2017)

Both are historical fantasy dramas that involve characters who can change their face to another person as well as court politics. In both there is a SML who is obsessed with the FL.

-Both dramas feature a male lead who is a slave to the female lead.
-Both dramas feature male lead with Amnesia and hidden past. In Colourful bone, the male lead turns out to be the prince who disappeared when he was young and presumed dead. While in An Oriental Odyssey the male lead turns out to be a prince of another kingdom.
-Both dramas feature a love triangle where people say that the male lead is not good enough for the female lead due to his low status.

Both are historical/fantasy dramas centered around a trio of leads - a powerful, violent tempered emperor/prince who is obsessed with the FL and threatens to destroy those close to her, his powerless yet loving younger brother, and the FL who tries to protect those she loves but is often a victim of fate.

Both are fantasy/historical/wuxia dramas with a more unique plot, aesthetic, and characters, and a similar feel. Both deal with complex court politics, birth secrets involving the rightful heir to the throne, assassins, and feature a love triangle. Both FLs are compassionate and become stronger over the drama despite suffering a lot. The MLs are tortured slaves/servant bodyguards whose only purpose is to shield and die for their female masters, and both end up belonging to the FL early in the dramas. Both love stories are angsty and heart-breaking, and the dramas have unique endings - Bloody Romance is bittersweet, open, but hopeful, Colourful Bone has two endings, one sad/bittersweet and the other happy.

Both dramas are historical/fantasy involving face/body swapping and a love triangle between an emperor SML, his warrior brother ML, and the FL who is initially closer to the SML before she meets or falls in love with the ML. Both dramas have similar themes of obsession, revenge, mistaken identities, and a plot point where a male character keeps his female love interest who is believed to have died on a bed of ice, then revives her near the end of the drama. Both dramas conclude with the FL and ML marrying and having a child.

Both are historical/fantasy dramas that involve a seeming magical ability to exchange faces between different people.

Both are historical dramas in which the FLs have the skill to change faces (either their own or the faces of others).

Both have star-crossed lovers as the main couple with a one-sided love triangle between the ML who works in/ends up working in the palace, the high-born but unpowerful FL, and a somewhat foolish and childlike emperor with a violent temper who was childhood friends with the FL and is now obsessed with her.

Both series have a character that can disguise themselves as anyone and also can disguise others as well. The main leads are connected to the royal family whether by blood or by obligation. Both stories have a lot of twists and turns. also alot of unexpected revelation's.

Both MLs were brainwashed/manipulated by a father or father figure into becoming an emotionless weapon which gives the ML great power. In both, the end of the training was the ML being forced to kill his own father in order to destroy his emotions/soul.