In some versions, such as the Reborn as a Tentacle Monster series, a near-blind college scientist is reborn in the world of Zareth. He gains "Evolution" and "Regeneration" skills by devouring other creatures (like slimes), allowing him to regain sight and eventually become an overpowered "Beast Born" with a human soul.
Certain adult-oriented versions, like I Became a Tentacle Monster that Corrupts Magical Girls , follow an unemployed man named Hakuto who accepts a deal with a mysterious gem. He gains dark powers and spends his time hunting and "managing" a harem of magical girls. Core Gameplay & Story Mechanics I Reincarnated In A Game World as a Tentacle Mo...
A whimsical take on a powerful being living a humble, protective life. In some versions, such as the Reborn as
A Korean web novel (serialized on Nobelpia) that won awards for its mature fantasy elements. He gains dark powers and spends his time
Most of these "Game World" stories rely on standard Isekai tropes integrated with a leveling system: