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volibear is high tier. i forgot nunu existed and i should play him since hes op. i need to go righteous glory on voli vs stuff like vayne. and i agree with his amumu paragraph. i have trouble vs high elo players with him.
if seems like you're interested in learning the uber meta. i can help out if you want. mibbit.com --> synIRC --> #ubers is a great way to find me/others and chat real time.
source: my dick