Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 4 - 4-6. Carriage and Coachman

Born of a great family, world shaking genius.

I, the protagonist, was just an ordinary NEET, but suddenly I was reincarnated as a tiny white snake in a fantasy world where legendary creatures and gods exist. Not only that, but I awakened in a cave as the offspring of a terrifying Medusa Serpent.Armed with only my human knowledge and my indomitable mental strength, I'm forced to use cunning tactics and rapidly evolving skills to survive against far stronger monsters and humans... So begins the survival story of a former shut-in with incredible willpower, living as one of the lowest-ranked beasts in a world of magic!ᆖMusic suddenly started playing in my head.I'd been waiting for this moment for so long.'Snakes! Assemble'....

One of the few self-cultivator who exist in this modern world; due to an unfortunate event, completely destroyed his body in an explosion. Using all his effort to save his primordial spirit, he ended up in an strange magical world and had to start all over again. From a fallen aristocrat to the Warlord of Chaos, this can no longer be summarise as legendary; this is the life of the God of War.

- Description from Novelupdates