Both dramas have fantasy, friendship, comedy, wuxia, martial arts and youth elements. Both dramas have past stories and developing plots. There are multiple main leads and there is light slow burn romance. The plot involves people hating and hunting demons, while the main characters try to unfold the real villian's grand plot.

Story deals with demons, mortals and immortals
Strong, wise, kind hearted & badass female leads; Strong & devoted male leads
A romance/love story portraying that leads can sacrifice their lives for the others.
Love/Hate relationship & torture
Wuxia and xianxia elements

Both are romance, mystery, fantasy, comedy and wuxia dramas. Both have similarity in plot too. In The Legends demons are hated and misunderstood while the so called orthodox sects kill demons indescrimately and are honoured for that. In the shadows these righteous sects use demonic techniques to become powerful. The demons make a sect of their own to prove how they can be righteous, kind and just.