@Riot Please don't nerf Kayle because of an item build
Now i'm going to start off by saying that Kayle should be weakened and tweaked due to her overbearing presence in both the lane and teamfights, however, nerfing Kayle because a specific item pushed her over the top in terms of DPS will not help.
Once everyone began to build Runaan's hurricane on kayle she became an even greater powerhouse wave clearer with crazy sustained damage. If an item pushes a champion over the edge, shouldn't the item be looked at, and not the champion? The champion's synergy with the item is what creates a problem, but if the item, like Runaan's, is never used on any other champion anyway, shouldn't that item be changed? The champion shouldn't be changed to circumvent the imbalance, which would only discourage other builds on the champion.
The same thing happened to Ahri. She was just too damn strong with a DFG, and so Ahri was nerfed and placed out of competitive existence as she became too feast or famine with the necessity of a charm landing, and the disadvantage of missing one being magnified to ridiculous proportions. Now Mage ahri is useless as assassin ahri is the only way to build her to capitalize on the synergy with DFG, rather than the other way around. The changes to ahri completely removed her other build paths and focused the champion into one discrete build path to maximize efficiency on the feast portion of her playstyle.
So please, don't nerf Kayle due to a strong build path arising. If Runaan's is too strong on Kayle it would be best to just change the item as it is not used on any other champion anyway.