I read this manga like year back, but it had only few chapters back then and now i can't remember it.. MC in his first life was seen as "demonic?" cultivator and he had red hair, in the end was killed by somekind of buddha guy? In second life he reincarnated into noble family, he got little sister few chapters later and he was really overprotective of her. Later on he met somekind of princess on his birthday party and she is going to be his future romantic interest probly? MC uses sword? That's all i can remember. Helpp.
"Immortal, invincible" is a bit similar to "The Scholar's Reincarnation" but way better imo (of course, Volcanic Age is top 1). Honestly i agree with the comment above, i don't particularly enjoyed the scholar's reincarnation, quite monotonous for me.