Ok, so I've been playing around with OHKO's for a while now, and my biggest issue is that the best potential abuser has better things to do. Sheer Cold Kyogre is not a bad set, but it just isn't as good as regular Scarfogre. The opportunity cost of giving up Choice Scarf + Water Spout coming off of a massive 438 Spa just isn't worth a 30% chance to kill the handful of things that could switch into a water spout. While Sheer Cold does a fairly good job of killing Kyogre's counters, it makes Kyogre a lot less threatening to begin with as random offensive pokemon can usually beat it. On the other hand, I have tested Guillotine Gliscor as an anti-stall pokemon and it works wonders. Taunt lets it shut down Lugia, Ferrothorn, Blissey, Chansey, Skarmory, most Giratinas, Forretress, and basically any defensive pokemon in the metagame. This usually forces a switch, which gives Gliscor a free chance to fire off a OHKO or toxic something, depending on the threat and the situation. The only two stall pokemon I can think of that don't fear this strategy are Skarmory and Forretress, and both can do nothing to hurt Gliscor back (although Forretress can still spin).