-Strong FLs in terms of mentality (FL in TLB can also fight)
-strong focus on scheming
-some focus on revenge for TLB, while The Double is pretty much all revenge
-hidden coup

There are many identifiable similarities, but I feel like the overall vibe of both dramas are quite similar. If you're especially looking for strong FLs who can scheme, both dramas are great.

-both are romance fantasy dramas
-in both dramas, one of the leads supposedly has a bad fate (BoR-FL; TTEOM-ML) and the other lead is supposed to help them onto the right path (BoR-ML; TTEOM-FL)
-in both dramas, there is a mortal, demon, and heavenly realm

-FL both fave hardships that the ML helps solve
-Smart and Strong FLs
-MLs will do anything to help FLs
-FLs' mothers both died
-ML both have cruel-ish parents
-Er Niang like Yi Cheng faces a lot of abuse
-both Historical Chinese Dramas

-both MLs focus a lot on cleaning
-both FLs suffer from some pain, FL in hello Mr gu being debt, and the FL in use my talent is her mother's death
-both Fls are hard-working