Can someone help me find this manwha?

Since most of the data has been lost I've been trying to find every manga/manwha/manhua I read/dropped so I wanna know if you guys might know it and give me the name of it. It's betting a manga or manwha but I cant remember which
So I read this a while ago so I don't remember the premise but I remember that the mc was human looking while the other character was like a creepy tendril entity and also they share bunk beds or smth. At first the mc was scared of it until the humanoid creature gave the mc a flower I think. They both are in this prison/facility with many other people. I think a but later the black tendril dude engulfed the mc inside of it and the entity looked even more human. Can't really remember anymore since there wasn't many chapters to begin with when I read it a few years ago. If any of you can find it you deserve a kiss on the forehead