Pwn comes from the word Own, meaning An act of dominating an opponent. Originally said during the days of WarCraft, when a map designer mispelled "Own" as "Pwn", thus making history.
Chovilla comes from the name Pancho Villa. Pancho was a Mexican Revolutionary general dating as far back as the late 1800's to early 1920's. He was a train robber and a Violent man and also raided many places.
So with that being said, Pwnchovilla is when a kid gets pwned old school style. Pwnchovilla is when someone gets raided on or gets ganked.
"Damn son! He was pwned Panchovilla style!"
"I'm gonna Pwnchovilla his bitch ass!"
"Damn, that kid Pwnchovilla'd us!"