Well that's not her purpose, it's more ks champion and 1 on 1 only like u said someone who aint armored also she is nice supporter in ganks so..

too squishy

this build is meant to kill squishes who don't have armor i play offtanks mostly so with this build the best you can do is ks me from your carry or stun me it is more effctive at killing squishes but you will die in 2 sec cause you will get focused irelia needs tank items this build is not effective at 1v1 either as carries won't walk alone and if you encounter a true 1v1 [xin,lee] you will get killed very easily cause they will have armor
and with the change of the ult doing physical damage you will get counted very hard you also lack AS for your W
also what makes the ult so good it is that it can proc trinity 5 times by itself

PLEASE COMMENT...REALLY WOULD LIKE AN OPION DON'T BE JUDGEMENTAL THAT'S MY FIRST BUILD :D