Invulnerable Units - Kayle possible glitch (and rant)

So I was on this game, RNG blessed me with a lvl 3 unit Stage 3-1, an almost 20 win streak and then I stalemate with a guy, huh ok, there's still things to do, I can work improving my units still, leveling up, etc. At that point, there were few adversaries on the game, so I basically ran into him thrice in a row. Then I noticed his lvl 2 kayle, with Shojin's, Rageblade and some other AS item. Following, I noticed the broken thing could literally just spam its ultimate, before the previous one was finished. That's shit's busted I though. And finally I noticed that, after some time, my units weren't doing any damage at all, even to "unshielded" enemy units; 0 dmg at all, negative dmg since some units were healing. You could imagine how utterly annoyed I was after that. Even at this point, I'm not sure what could've happened, but that thing is broken, in its mechanic core/definition and either visually bugged, or definitely mechanicly bugged. Has anyone else run into something similar involving kayle?