Both are republican era dramas
Both dramas have romantic relationships and Slight Bromance
both deal with war an fighting the enemies

Both republican era drama
both have Bromance and also romantic relationship
both deals with War

Similar vibes ,, Investigative work
genius young detective
both drama are thrilling dramas very interesting

Both dramas about detectives in historical times
both dramas have good friendship between male leads

Both dramas about the royal court affairs
and detective investigations
Both have Bromance between male leads I think

Both dramas are about investigations in historical times \

both drama has good friendship between male leads

Investigation and mystery
the leads in both are trying to uncover the secrets of the kingdom
both are historical detective dramas

Both have strong male lead
Both wuxia dramas with wuxia fights
both has good romantic stories
Both have strong female lead

Both drama are badass Wuxia drama to the core story
both have strong male lead and strong female lead
both have amazing Wuxia fights
both are great watch

Both dramas are about fire fighters
but I hope Blue flame is better than flaming heart
because the romance destroyed that other one

Both Military drama but one in rebublican era and the other one is in present times
Both have good comradery and both have unique friendships fighting the enemy

Both dramas have brotherhood and comradery
both dramas fighting the Japanese occupation
Both have strong male leads and conflicts also both have traitor
one is war the other espionage