• In SM UU, I guess it's Steelium Z / Fightium Z Cobalion. Resist K-Off and get Justified Boost + Z-Stone can't be K-Off away.
• Keldeo Waterium Z isn't as good as Cobalion but it's kinda good too.
• Normalium-Z Azumarill don't care a lot of Knock Off (but be careful vs Bisharp with Iron Head).
• Gliscor and Mandibuzz can be good too (for the first one only if it's ability is activate).
But i'm not agree with K-Off spam in SM UU. As I can see in the UU Ladder, K-Off isn't use as much that in XY and ORAS UU.
• Keldeo Waterium Z isn't as good as Cobalion but it's kinda good too.
• Normalium-Z Azumarill don't care a lot of Knock Off (but be careful vs Bisharp with Iron Head).
• Gliscor and Mandibuzz can be good too (for the first one only if it's ability is activate).
But i'm not agree with K-Off spam in SM UU. As I can see in the UU Ladder, K-Off isn't use as much that in XY and ORAS UU.