Recommendations

Both shows focus on a demon controlling (Possessed) or taking the shape of other people (Metamorphosis). The tone of both the movie and the show is bleak and dark; with the end game always revolving around having to make sacrifices in order to win.

It's by the same director and both shows focus on supernatural/exorcisms.

The main antagonist (demon) is also targetting the main characters in both shows. In the case of Metamorphosis, the demon targets a Priest's family; in the case of The Guest, the demon targetted the three main protagonists' families and then he zeroes on one of them (a Shaman).

Mistress is about four women with scandalous background teaming up to do an errand. Both series revolve around 4 women with different background gathering to solve a problem. However mistress has more criminal and mysterious atmosphere.

Both are based on revenge theme where some women with different backgrounds team up to take revenge of their abusive husbands.

This two may have a different genre, but if you're a fan of poetry. I think you'll like this. The way how the ML describes a certain happening in the story is like reading a poem.

Justice and injustice, innocent, society, sadden, powerless, care, love, powerful, law, legal, fighting, truth, court, cell, survivors, past, mistake,

Justice system, determination, human kind, inner self, law, higher pressure, right and wrong, conscience, poverty, power, motive, evidence

Both drama focus on female lead fall in love with the man who has her ex-husband heart.

Both are long dramas with family involved.

Both are based on historic figures and the time line of the story from both shows are set in around the same timeline but told from different sides (queen seon duk is silla and gye baek is Baekje and both countries historically have interchange with one another) , different perspectives.

Both are narrated from the third-person observers and the 'main' actions (Kirishima's struggle in Kirishima Bukatsu and baseball game in Alps Stand) aren't shown to the audience.

Ji Chang Wook is the main lead in both the show and movie.
Although it does not follow the same plot of an undercover agent, and instead a gamer framed for murder, it is similar to Healer's 'teamwork' of allies working together to find the truth (including a hacker)
However, fabricated city has a much more serious tone than Healer in terms of action, and a warning of quite gruesome and emotional scenes.
But if your looking for more Ji Chang Wook content or something action packed with good fighting and car chasing scenes i recommend fabricated city.
But if you still want that romantic vibe of a classic kdrama then Healer is the one.

When you don’t realize the love that you have in front of you till it’s gone... that’s when it hits you like a brick of how much that love really meant to you.

One of the leads in both shows is some sort of animal. Both really cute plotlines but I'm a pet at Dali Temple is more serious that Semi Otoko.

They have a lot of things in common, but especially the second female lead
Just that in HL more people knew about the secrets, as in MDGSW.

Both of these have leads which are complete opposites in their studies, but rather quickly become friends and begin to like each other throughout high school, but after graduation the leads lose contact only to be reunited again later. Both are very very good though they have slightly different vibes and formats, but still totally worth the watch!