[{quoted}](name=Lumus Avatar,realm=NA,application-id=3ErqAdtq,discussion-id=89mk4K7I,comment-id=0001,timestamp=2015-03-03T19:50:32.287+0000)
I don't play Yi, so I can't really help you there. As far as I can tell, just Alpha, Alpha, and Alpha some more.
I do so I can give a bit of help:
Q: Lets you dodge things with its invunerability (well, untargetable but whatever.) It lets you dodge stuff like
ult,
stun,
(I believe) the burst from ult, turret shots, and just skill shots in general. Even allows for some mobility if you need to escape (say in the jungle, put a ward down, then Q to the monster over the wall.)
W: Both a damage reduction and AA reset. It allows you to get in another instant AA (no duh), and possibly survive if you don't have a target to Q to with the reduction. Things like
ult (again),
ult burst (again), or even abilities that would stun.
E: Just basically a damage amp that lets you ignore armor and give a bit of free AD when not on CD. Just don't use it before you alpha as the true damage won't work. (So go Q, then when out of Q use E)
R: Free damage steroid, ignores slows, allows for partial resets, extends in duration and yeah.
EDIT: ALMOST FORGOT MooMoo