Both are short dramas, with very good actors and interesting story.
It also have the love/hate relationship in the beginning, that leads to great chemistry!

Both are xianxia. There is the heaven and demon realm and a predetermined marriage arrangement. There is a dark force seeking for war.

Both are xianxia dramas. The ML have a nice chemistry together. In both the ML they can't be together due to their story and role.

Short drama with time loop.
The FL also have to find a way to get out of the loop and fall in love.
There is mystery to be solved.

Both have amazing actors as main leades.
Both stories are interesting and have a good deep feeling. You get intrigued of what is going to happen next.
The production is so good, everything is well made.

Although this is a long drama, it has the same elements of xianxia, both FL are phoenix characters, the MLs are important immortals.
The actors are very good, the production as well.

Both dramas have interesting plots.
There is an intense feeling to it, it's not a light drama.
The FL is hiding things from the ML and the ML is suspicious of the FL.
The relationship have ups and downs.
There is a second couple.

Both are about Martial arts and powers.
The ML is weak and become really strong
There is a martial arts contest and different sects.
They find friends along the journey to become better at martial arts.

Both are very similar:
Arranged marriage
Wrong bride
The wrong couple falls in love during the relationship
There are betrayal plots inside the family and the new bride helps the husband

Powerful male lead
Cute female lead
Cute couple
Mystery and secrets to be reveled
ML tries to save FL and vise versa
Very well produced, great costumes and visual effects.

Both are very similar
The FL can't be with the one she loves because of the obsessive love of another men.
There is a lot of betrayal, court problems and power struggle in both.
In KW you recognize the enemy because he is the main character, but in PS you only gonna find who he is a bit later.
The Princess Silver is somewhat lighter in the beginning, but it turns out very painful.

Both have protective and dedicated general ML (although OLY is a bit more possessive)
Both have non-human FL
Both plots regard fighting another clan
Both are mid length dramas.