Her shield is cancerous on a snowball phase and there is nothing you can possibly do against a fed champion with morganas shield. Cant run or fight back riven for example, she'll just go up to your team stun and kill you because her shield will eat every single CC thrown it's ridiculous. Her shield should only block 1 CC maybe 2 at max level but even then that's too much, some champions only have 1 trump card to save their asses and whoever she shields can just void the immobile champions chance which is good enough but when the whole team tries to save them and there's nothing possible to do about it i feel there is something wrong here.
The second thing wrong with the shield is that is Used as a balance mechanic or excuse on other champions. Nautilus or blitz bot? well that's what morgana is for. I don't feel this is the correct method of balancing champions. If blitz and nautilus are a problem bot there should be a method of outplaying them or punishing them through their own mechanics or kit not needing to extend a single champ to become their weakness.
My 2 cents, yes I just had a horrible match were riven facewalled my team with a morg shield through vaygars stun, my soraka silence and the irelia stun/slow or lee sins kick she just charged in.. it was a mobile gap closing unCCable champion that can Aoe stun, knock back and do massive damage with an AD scaling shield and AOE massive damage ult. ohh gee