"We've had trouble balancing Kayle in the past because of her ulti"

That heals everyone in it including enemies, everyone forgets that

Lol but it's Riot, so it's not really surprising, they suck at making games

the thing about kayle's ult is that it can be used at any moment to prevent damage. you don't even necessarily have to wait until someone's near death to use it when blocking damage from an important enemy skill is enough to screw at least one person over