Similar time travel plots and the leads saving each other in each timeline and romance between the leads
Although the plot lines are very different, one about amnesia the other death, I believe they evoke similar feelings as you go through everything with the ML (and side characters) on their journey of healing and closure.
IMO similar plot (both revenge just different reasons for revenge), with the same ML just on different sides of the court.
Both series have themes of dealing with the dead and romance with a past connection between the leads
