Why doesn't Lee have his shielding reduced in URF?

I know it's just a silly mode but holy lord is fighting Lee Sin frustrating. AP lee is for some reason the best support in the mode by far, with huge shields, incredible mobility, and good CC with his ult.

My only problem is, why doesn't he have the Shield Overload debuff many other champs have? His is just as spammable and powerful but he has somehow avoided this? And come on, it's not like he doesn't have a bunch of other things going for him.