Well you could use Forretress or Hitmontop. While the former is able to spin + lay down entry hazards, the second is also a good counter to sandstorm teams. You could also try a Defensive Deoxys. It can lay down Spikes + Stealth Rock, Knock Off opposing Leftovers and then stall all day with Recover while Hail damage kills opponents. Sableye makes a good anti-spinner, he also has Prankster so he can Will-o-wisp dangerous physical threats (Landorus, Garchomp, Lucario, Tyranitar, Excadrill, ...). Other options are Bulky Garchomp with Stealth Rock and Dragon Tail, but I think you're using Milotic as a phazer so it might be redundant. Jellicent makes a good anti-spinner, but another Water type could hurt you. Excadrill checks Sandstorm team and can Rapin Spin. There are plenty of other options, so it's all up to you actually. I would advice against using Walrein, weather teams are just to common currently for him to be used effectively. Good luck!