I don't understand why anybody in their right mind would use Sheer Cold on Kyogre.
What's the point of a 30% accurate OHKO attack on something that has enough raw power to OHKO or 2HKO almost the entire metagame?
On top of that, if you run Sheer Cold you'll obviously run RestTalk, effectively leaving you with precisely one attack move, supposedly a STAB attack.
Congratulations, now everything that resist water has a 70% chance of coming in and setting up on Kyogre.
Wouldn't it be more useful to run Thunder Wave, crippling any possible switch in without fail? Ground-types and Thundurus-T are definitely not switching on Kyogre. Assuming said switch-in can be 2HKO'd by Kyogre, the paralysis chance (25%) will give you an extra turn, so there is only a 5% loss in chance compared to the outright OHKO from Sheer Cold.
The only notable pokemon Sheer Cold would be useful for are Chansey, Blissey and Ferrothorn. The latter two are 2HKO'd by Specs sets and the former is nothing but a 100% predictable deadweight in ubers so if it actually gives you trouble there's something wrong with your team.