Rimuru Tempest in Multiverse

In a universe there are so many stars called planets and there's a lot of galaxies. Then there's called a milky way in that galaxy inside it where we called, solar system and the called Earth in the 3rd position in solar panels. Inside of earth. A young man who reading a light novel book called "That time I was reincarnated as a slime" while walking in the streets and there a unknown man who equip a black suit, black mask, black hat that holding a knife through to the young man who reading silenty and died before he realized it. his fav anime and novels and the character who love the most is other than Rimuru Tempest, a slime and A humaniod with no Gender. Disclaimer : I don't owned any character, world's, and Skills. This is only a fanfic I made in my mind so you can guide me and improved my English terms. I am not a Japanese or Chinese or Korean author that you can read in webnovel. I am a Filipino Otaku who love anime novels etc.