I've made a number of nunu rework ideas myself so i like to give feedback when i see others since there seems to be few people who care enough about him to realize he deserves a rework.
P: not bad, I'd like to see this have the same effect/duration when coming into (near) contact with an ally as current bloodboil or perhaps it could be toned down but be persistent for nunu and also effect allies when he is near to them.
q: the slow animation and reliance on bitable target as well as terrible range would make the efficacy of the hsield rather useless since he'd likely take more damage than it would provide. This skill would be relatively useless outside of jungle. Assuming it could be used on enemy champions perhapsif the shield was like 20% of his hp which is pretty regular for shield strength, half of it could be normal shield and the other hal could be spellshield so its range wouldnt make it so useless in regard to the likelyhood of him being cc'd allowing for further damage to easily melt the shield
w: not sure what the snowball zone is, is it from his e or is this a completely different aoe? Also, i like the hard cc which nunu severely needs(or mobility) but currently lacks. The base mechanics of stun/root are very appealing, with the right range this could be a good skill.
e: so it seems that aiming and slow effectiveness would be better in teamfights. not sure if you mean for this to be skillshot or not or perhaps your talking about an aoe? which would likely be what you w is referring to? Also if your w skills simply augments your e then it needs something else since having one skill that does nothing without activating another skill is not good
r: honestly not great. to improve it you could cause the target to be grounded and silenced while buried in snow after the knock. Even assuming this does moderate damage, theres no way riot would let it be targetable unless it had the same mechanics as reksai ult and if it was a targeted dash similar to ww it would basically just be ww ultthat trades damage for cc which actually isnt bad in general. The problem i'd still have though is that for nunu its not consistent thematically with him historically. His ult is absolute ly one of the most unique nuke skills in the game and removing it in favor for something so similar to another champs ult as well as it being so different from his current ult isnt ok.
overall for a really rough rework there are some hidden gems :) if youd like to see my last rework the link is below
https://boards.na.leagueoflegends.com/en/c/skin-champion-concepts/UKfv3XjE-nunu-rework-v30
that build omits consume but in the comments i talked about how it could be worked in as a passive since so many people find it important
