Both dramas are during the post modern Shanghai era. They both involve strong powerful men. The romance in both dramas are similar as in the men is dedicated to their leading lady despite all odds.
Same era and similar set up between the leads. And the same exact location set!! The first obvious difference is the age of the leads. Cruel Romance seems to suggest an older cast. While Fall In Love seems to suggest early twenties for the leads.
Both dramas feature a villain that was obsessed with his lover and became crazed when she died. Both female leads look exactly like the deceased woman, but in The Flame’s Daughter it is because the FL is the woman’s daughter while in Cruel Romance the resemblance is pure coincidence. Both villains are convinced that they can turn the FL into their deceased lover. And both villains are handsome and devilish.
In both series an arrogant, abusive and weird male lead of significant wealth, position and power is hideously treating a resourceful but childish female lead until she falls in love with him for no reason at all. All characters are nearing their 40s and are of course virgins and never had any prior romantic relationships. Really similar main couple dynamics.