Both drama are romantic thrillers.
Both dramas have married lead couple who are hiding secrets.
Both dramas revolve around uncovering the secrets.
But flower of evil, the marriage is well established meanwhile here it's not. Flower of evil is more crime based than this.

It is written by the same writer. And both the drama gives off that warm and cozy feeling. If you loved any one of these 2 dramas, give the other one a try.

A former spy hiding his real identity to his wife. Kinda give similar vibes in husband and wife relationship

We have some of the main characters in this show. Ji Jin Hee and Son Sok Ku. Their chemistry was insane throughout the whole drama. This is hands down the best political kdrama out there. Even if you are not a fan of political dramas. The comments section is full of such good reviews. You definitely gotta watch it. The character development, the chemistry, the story, the thriller element was on point.

Somehow the drama feels so alike with this reincarnation theme. And the lovers meetings again in the present life.

This is a movie
But one lead is changing appearances regularly and he finds it difficult to find true love.
But when he does he's wondering how to keep this love with his changing appearances.

The setting is pretty similar. The female lead have special powers. Both the dramas have a historical background.

Very similar theme. Except for mafia, you get a very similar legal drama filled with comedy. The only contrast was their love hate relationship.

Both are female centric action dramas. Plot is pretty similar. Both the leads seeks revenge and gets involved in police operations with their hidden identities

The 2 dramas are pretty similar
ML - has a secret past
FL - has a busy job related to law
FL and ML - married happily with kids
And the plot goes like something comes up related to MLs past life and story goes on with FL finding her man's secrets and etc etc etc

I got the same vibes. It's not so action oriented. But definitely has some thriller element to it. It also involves political corruption. All in all if you enjoyed this drama Designated Survivor:60 days recommended.

The drama are very similar. A young girl travel back time and falls in love with a man. Both dramas have that aspect. And the man has problems with his family. Holy pearl is a very interesting story. I think it's much better than Scarlet heart Ryeo.