Thank you for the rate Jimbon! While I can see your point, I'm not really sure swapping Sableye for Gengar is a good idea. While it's true that Gengar is kinda tricky for spinblocking, it can check many other things that Sableye couldn't even dream of. For example, a random Choice Specs attacker is a great pain for every Sableye set: it cannot cripple it with WoW and will be OHKO'd by any decently powered attack. Also, while it better checks defensive DNites, and to a lesser extent Tentacruel (praying that Rain isn't up, obviously...otherwise it's not gonna appreciate the match), it takes 79% minimum from offensive Dragonite Outrage (OHKO 44% of the times after SR), and if the thing is carrying Lum Berry (which is not rare), your chance to stop him is not that high even if it goes for DD first. Okay, I could revenge later with Latios anyway, but I could do that even in Gengar's case. Also, Gengar is completely failproof while checking Gliscor, while a single Toxic on the switch can screw you badly with Sableye, and my team can be easily Toxic Stalled with a bit of luck by Gliscor alone (and maybe a Steel partner to take Draco Meteors. Not to even mention that yeah, Gengar always loses to Starmie, but Sableye has a chance to be OHKO'd after SR, and it always is into Rain. I often prefer to deal with such offensive sets in other ways, for example by preserving my Mew and killing them with a surprise Draco Meteor, while setting up Rocks later. Also, if Starmie switch on basically any pokemon of my team, it MUST gamble to use Rapid Spin, since basically everything can OHKO or severely cripple. Gengar is still useful to stall out things in general and to block unoffensive Spinners like Donphan or Forretress. Sableye could do the same, of course, but still it must rely on inaccurate WoW and has no other means to deal consistent damage. I think this paragraph is not written very well and kinda confused, but I hope you understand why I'm going to think quite hard on your suggestion before implementing it.
However, on the second part of your post, you're absolutely right: I need an Ice attack somewhere. I will test it on Keldeo first, but if it doesn't work, or it's still not enough, I could test it on Gengar. WoW on Gengar is quite tempting also, since it will give it alternative ways to check threats like Toxicroak or Tentacruel. I'll think about it as long as my schedule allows me to do so, thanks for the input and the many great ideas you brought on the table!
Not accepting rating requests anymore. Sorry!