Kyogre (M) @ Leftovers Trait: Drizzle EVs: 252 Hp / 252 SpAtk / 4 Spd OR 252 SpAtk / 4 SpDef / 252 Spd OR 252 HP / 4 SpAtk / 252 Spd Modest Nature (+SDef, -SAtk) - Substitute - Calm Mind - Surf - Thunder/Ice Beam The beauty of SubCM is that Kyogre can get a Substitute up so easily because it causes so much fear on a switch. By the time they switch to a counter for Kyogre, it's too late; a Calm Mind on Kyogre is equivalent to a Choice Specs and even higher Special Defense that takes hits for the Substitute. If you are able to completely set up on the opponent, they should just give up. Surf is the most reliable move to use for Kyogre because of its overall consistency. The last moveslot is your choice of coverage, because everyone likes coverage. I personally prefer Thunder because it hits more targets and the paralysis is extremely useful in conjunction with Substitute, but Ice Beam can be used instead if you rather that for coverage. Either of the EV spreads above can be used depending on your preference, but the first one was posted on Smogon so it has to be the right one is the best of the choices.
Nice to see SubCM Kyogre getting some love. Personally I like the 252 HP/ 252 SAtk/ 4 Spd spread best - you hit harder after fewer boosts, and can make 101 HP Subs. Once Ferrothorn's down it owns.