similarities:
both shows have the same martial art world settin.
both shows display the enriching tale of brotherhood.
both have the same contrasting negative and positive ML DUO.

Both are medical dramas
Couple seperation
Senior Mentor guidance to the FL
Smart FL who actually proves her stand etc

Similarity:
1) Both drama share the similar plot of role reverse between FL and side female character in the novel world ...
2) The comedy and light heartedness is also pretty much the same
3) both are based on "FL's mission completion in the novel world in order to leave it "

Dissimilarity:
1) night of love doesn't offer the entry of original writer in the story whereas PFIL has the orginal writer playing as FL so she knows pretty much the entire plot
2) night of love is love story between vamp and villain ..please fall in love is love story between ML and side character

The plot is quite same in both series FL is back to life from hellish fire. But in revel princess she wakes up in other person's body.
As far as the intensity of emotions is considered Rise from the ashes was better,the FL lead actually turned grey ? and she was more ruthless considering she is back from the death. I missed it in the revel princess plot.