Misunderstood MCs

MC is confused for a very OP monster/being when in reallity he's just an introverted guy trying to live his cottagecore life inside his paiting. His only power is whatever he paints becomes real/physical.

Or is it?

MC is an alien that possessed a human body to escape his planet since he was feeling overworked iirc. The MC is very versed in mana magic and was the very best from his planet. The only problem? Even though the human body he possessed was compatible with his abilities, the human had very limited mana since he was an F-ranker. Watch as an F-ranker gets mistaken for an S-ranker when the alien starts using tricks and cheats from the knowledge he possesses.

Creepypasta reader enthusiast gets trown into a bunch of them and since he's an cowardly scaredly cat he vows to speedrun the stories with the knowledge he has about them to spend as little time as possible inside them. The misunderstanding? People think he's very brave when internally MC is shitting his pants.