I have a proposition to stop all this infighting amongst the powers that be, so they can once more unite and do things like count Teemo deaths with high accuracy.
What about a bear... That isn't armored ALL of the time? Maybe his ult lets him don armor for a few moments, and then it's gone. Or as his rage bar fills (because we all know bears would be powered by rage) armor is added as the bar fills (every quarter?), or armor is removed every quarter of the bar that fills and can be expended for abilities so that he is most destructive while he is most vulnerable.
Also, I think it wouldn't be too unfair to add a killswitch into said armor in case of an unstoppable rampage. If it wants to be a bear that can't be killed by wearing armor, you could then just... Kill it either way.