If anything needs to be changed about Irelia it's her passive. Nothing else.
Q, W, E and R all support a Duellist playstyle, whereas her Passive more heavily revolves around teamfights.
If anything needs to be changed it's this. Make it a flat, mediocre amount of Tenacity if you must or give her a Passive relevant to the rest of her kit. Just don't kill her identity all together.
fight me
Happily.