Why not make Nunu's W give a small amount of resistances?

Nunu is basically garbage right now. A tank with no damage, hard CC nor protective abilities. He really needs some kind of a change, but what should it be?

My idea is to make his W also give a small amount of MR and armor in addition to his MS and attack speed. For example something like 5/7/9/11/13 MR and armor could work (The amount can be changed of course.) It's not anything major but it can help Nunu get back in the game. I personally don't want a rework on him, i think he is fine just like that. But he needs a buff of some sort.

Now i know he got a buff recently but the buff was an absolute joke and i don't think it helped him at all.[zombie-nunu-bummed]

And for those who want it, here are the winrates:

Champion.gg from Platinum + Nunu Jungle: 45.63% Nunu Top: 40.48% Nunu Support: 39.07%

Op.gg Nunu Jungle: 48.46%