Well, I see Warwick and Yi being much alike in the way they are built (Crit, AS, AD, Lifesteal). I have also faced many built in such a way where the Lifesteal was completely countered by and by this point (assuming you are hitting as hard as you say you plan to) you are just killing yourself.

But still, the item build is pretty straight forward. People might have ways of countering such a risky move when it comes to crit and crit chances.
You will have to be very lucky or very good to finish the build, which will of course be good at that stage, but what bout the matches where you just get an average start?

Thats the problem with Master Yi builds that go the same way. One little slip, and you're out of the race. Just like that.

But still, the item build is pretty straight forward. People might have ways of countering such a risky move when it comes to crit and crit chances.
You will have to be very lucky or very good to finish the build, which will of course be good at that stage, but what bout the matches where you just get an average start?

Thats the problem with Master Yi builds that go the same way. One little slip, and you're out of the race. Just like that.

hmm ^^..with this damage attack speed life steal and critical chance and critical damage i don't think u gonna need the armor and health..come on man.. 40% life steal are u serious?

Items aren't bad... kinda anti-tank-ish, lol. Needs hella more armor/health though (assuming this is even remotely tank based).

Runes: WTF!
9 Mark, 9 Seal, 9 Glyph, 3 Quintessence

but hey, you got my attention.