Ok so basically what happened with the Polish dude and Eminem is:
‘The year is 2014. Eminem is still riding his revived fame thanks to his late 2013 single, Rap God. Eminem is going around saying that he’s the best rapper currently alive in the world. An upcoming Polish rapper named Cypis sees this, and takes offense to it. At the time, only 5-6% of the world spoke English, and Em was monolingual. So he starts talking about that in a YouTube video, and midway through it turns into a semi-diss track against Eminem, ending with Cypis putting on a rap spectacle of his speed and lyrical ability similar to what Em did in Rap God. This went largely unnoticed outside of Cypis’s home town however, because he did it in Polish, and because he didn’t use clickbait by titling it with “Eminem diss track”. 6 and a half years later, dancing Polish cow becomes a meme and some ppm find out about it, but Eminem doesn’t, so end of story. But let’s look at a rapper who had a beef with Eminem in 2018, MGK. MGK was a big Eminem fan until Eminem made a reference/diss to him on his album, Kamikaze, talking about how they weren’t alike, despite MGK desperately trying to make himself look like the “second Eminem” or something like that. There was literally a song on there called “Not Alike” about MGK. MGK responded with his diss track, Rap Devil. Well, part diss track, part MGK talking about how they are actually alike. Eminem decided not to respond, saying that “I don’t wanna give him more clout”. Until he saw that MGK had Tweeted that Eminem’s 16-year-old daughter was “Hot as H*ll”. Eminem, being a good father who’s protective of his daughter, made a diss track called Killshot and just Destroyed MGK, also end of story.