MC was sleeping in some tomb/coffin down underground? Humanity is facing another race that wants to enslave them. (Some elvish looking race?) MC gets woken up by a team of explorers so he (I think they mistook him with another person) can save humanity or something. It was written in a particular way, every 3 chapter would be (1: Present time, 2: POV of another person, 3: MC's past). I don't really remember much more other than this. If I recall correctly, the MC wasn't the person they were looking for but MC taught them some magic to defend themselves?
I think I know which one it is, the MCs entire race got killed and the explorers who found him was part of an expedition sent from another continent. His race is good at weaving mana. If this is familiar it’s probably Grand Weaver Edit: Just looked it up, it got a rewrite so it might not be as familiar anymore. Got dropped pretty early after the rewrite began aswell
Not sure if the novel is still in RRL but I believe you are looking for The Destroyer from Michael-Scott Earle https://www.michaelscottearle.com/the-destroyer
..... I should have that one in my reading list... Ahhh so that's why I dropped it... the author had book one up on RRL and the subsequent books were all purchase only.