going medieval
Refers to an upcoming violent behaviour on somebody's ass. Medieval civilisation is known for it's cruelty and violence, therefore when going medieval on someone, the results can be truly devastating.
Example:
-"I'm sorry man, I had sex with you're wife"
-"(Picks up a baseball bat) That's it! I'm going medieval on yo' ass"
-"I'm sorry man, I had sex with you're wife"
-"(Picks up a baseball bat) That's it! I'm going medieval on yo' ass"