Someone says a word, and then the next person says the first word that pos into their head when they see it. Then ext person say the first word that pops into their head when they see that word, and so on.
i.e. first poster: cheese
next poster: mozzarella

I'll start
rock

Well uhh, Malphite of course.
And another thing I'd relate to rock, which I'll pick as MY word; Music.

Pentakill Olaf, umm yeah sure.
Spin

garen

purple

lulu
dunk

Darius
Penta

Acu

Flacid

Fiddlesticks

they don't have to be related at all, or have anything to do with league.

crow