im kinda confused on how the crit will applies, so each critical strike durning his ult gets 15 armor pen ? or is it after his ult , that he gets 15 sec of free armor pen on crits ?
on a side note, when does yasuo reach 100% crit, like with what items ?
each crit will have 50% bonus armor pen for 15 seconds after his ult
and he gets it with 
and 
It stays the same, except only attacks that crit will ignore bonus armor, instead of all attacks.
For 15 seconds after ult, all of Yasuo's crits gain the bonus armor pen.
Yasuo can normally reach 100% crit with two crit items, IE and PD are the normal build for this.
can get the full 100%crit and get the full 50% bonus armor pen with just building 2 items and any of these / 
/ 
but the reason of the change is to kill the tank yasuo having 60% crit with 1 item () and still destroy any tank with insane mobility
