Sunlight stabs your eyes like tiny little needles. Closing your eyelids doesn't do shit against how annoying it is. Raising your hand helped but did little against the slivers that passed between fingers. The futility of your actions only served to annoy you further.
You groaned as you rose. Your joints hurt, and you feel like you've been hit by a cartoonishly large truck on your way home. You remember going to work, passing through the streets and shortcuts that would put you at your destination five minutes earlier, but this meant you needed to pass through the busiest highway in the city. You remember passing the street; so far, so good. Then you heard screeching tires in the distance. A few feet away, a 66-tonne white truck hurtled like a speeding bullet toward you. It was a mania of destruction and carnage in the path it left behind, and it was keen on doing the same to you. You admit. If you jumped a millisecond earlier, you could have saved yourself. Probably lose a foot if you were sloppy with the jump. But fear chained you to the asphalt, and all you could do was scream as everything went black.
Shit! You did get hit by a truck. You've read hundreds of isekai mangas and light novels, and you can't believe you died a cliched death. What? Next thing you know, you find yourself in a fantasy world of might and magic while stuck in the Middle Ages. And kid you not. The moment you thought those words, the skies darkened, and winds began to howl. You look above and see a massive crimson reptilian beast soar through the skies and slice clouds without a second thought.
"What the fuck!?" You said, your voice hitching at the sight of such a titanic beast. What the fuck, indeed. You hid under a tree while noticing the lightness of your weight in your strides. You would focus on it if you weren't so busy with hiding for your life. You waited until the skies settled and the beast was miles away.
You look around and realize that you are in a forest. How cliche. What's next to this sort of thing? Yea! The overpowered skill. You uttered "Status," hoping a magical blue window only you could see would appear before you. None appeared. You waved your hand, hoping it would do the trick, but were startled when you realized your hands (or the lack thereof) have now turned into bluish tentacles. You looked at your other hand, rather — hands. But they weren't hand. They were tentacles — blue, shining, and slippery like a jellyfish. You touched yourself and realized you're a squishy little thing no larger than a small dog. No wonder the trees in this forest looked gigantic.
Upon realizing how you looked, you were invaded by this painful idea clawing and searing itself on your mind. You have since discarded your human form in exchange for the most nefarious and invasive creature the land of Fiore has ever seen. You have become a body invader. You could crawl into somebody's orifice and take control of their bodies from the inside. Magic defenses, willpower, and anything that tries to impede your invasion are useless. Any living being larger than you is ripe for the taking.