Actors

+ systems
+ subtle BL
shaman to celeb

+ reincarnation
+ systems

+ system

+ regression
+ system

If you're interested in theater it tackles some of the elements. You can learn a lot from this it's not the same as the other actor+system trope, the actor really understands what's it like to act and works hard to be better, he does not rely on his system.

+ systems
+ regression
Idol past life to actor in new life

+ reincarnation
+ systems

+ bromance
+ action

this one's so funny lmao, a gangster who lost his memory and an actor accidentally swapped life's. No freaky friday but they look like each other so the people around them mistook them for each other. not really focus on acting like the other manhwas on the list but still the actor is acting like a gangster so