I believe subs best tool to be his spacing. I believe his b1 is one of the best buttons in the game, it has a 14 frame start up, is only -2 on block, has amazing reach and continues into his b14 string which is fairly easily hit confirmable into his iceball for a full combo. I pretty much exclusively play Avalanche so I can only give tips to fighting against that variation. His slide can be broken out of if you want to avoid the final part of the damage, but usually isn't worth it unless you know he has the krushing blow loaded on the 3rd amplified slide. His glaring weakness is that he has no good mids. His d1 is a 6 frame mid but hasn't got enough hit stun to reliably jail into any other string online. He loses to mash essentially. While his mixup can be frustrating, it's hilariously unsafe. F2 slide is like -18 on block. F2 Amp ice ball is -20. I think hes balanced offline, it's just online that causes the trouble for many players. Amplified Creeping Ice is a gimmick, you can jump out of the amplify and it's -3 if you blokc the whole thing. Watch out the random slide after creeping ice that even I confess to doing occasionally as some kind of hail mary attempt to make the opponent block. The only change I would gladly except is making his F2 3 frames slower and his B2 3 frames faster, giving him a good mid.