I already wrote a semi-long thing about this, so I am going to shorten up a bit. Basically, you can probably report him for this. You will long selfish and annoying though.
Firstly, for anyone who may have said this to someone, pretend everyone is 8. When you place basketball with an 8 year old, and you stuff them, do you say "reeheheheheeekt nubscrub eZz"? Nah. You know why? It makes you look stupid.
What else is kinda stupid? You complaining about this. Sticks and stones can break my bones, but words over the internet will cause me to rage like the hulk. Wait that's not how it goes? Oops. Either way there will be a lot of toxic people in life, and some of them may really hurt you. Really, the only thing to do is nod your head and move on. He beat you, so therefor he can use it in his montage. He wrote LOL , who knows why, you don't really give enough info. Maybe you set yourself on fire. When he says whatever the nonsense is on the last line, I think it is meant to be Rekt, well, he may not have wrecked you, but he certainly killed you.
Be strong bud. You are probably better than him anyway, and he caught you sleeping in a chest.
It'll be ok.
-Demon