This build provides you with one shotting small targets (ADC'S,MID,etc) its only weakness is tanky targets, but you obviously won't be focusing tanks in team fights, right?
youre crit is suppost to be around 800-1000 and even more.
remember youre really squishy, so dont waste your Q's, plan them, and one shot the carries,
by the way, if you need to escape after you killed someone with Q, just throw a W, you can also ult if needed. Good luck!
this is a simply and fast build.