Goodness. If you all keep on repeating on the same reasons on why he sucks then I'll be handing out infractions. Think on something new before this thread gets cluttered up with "he sucks because his speed is lackluster" or "120 SA isn't threatening enough". Or better yet think of something positive and actually try to work this thing. Come on you all can do better than this
At the moment (not right now), I am using this spread for Origintina
18 HP / 24 Spd / 248 SAtk / 220 SDef. Modest (may have more speed than shown).
I'm not quite sure how it will work out in practice, since I only used it once yesterday, but on paper it can survive some handy stuff
369-371 SAtk Kyogre's Surf on this: 97-114.
This means, 87.5% of the time, Surf is a 5HKO, meaning you could Rest, Thunder, rinse and repeat. Just watch out for CHes, especially if you both have 6 CMs lol.
399 SA Kyogre's Specs Ice Beam on a CMed Origintina: 188-222. This is a 3HKO. Of course Stealth Rock has to go ruin that, but on the plus side you live with at worst 37.75%, which gives you a 75% chance of surviving an unboosed Dark Pulse from Timid Darkrai, in which you can return the favor with Dragon Pulse and OHKO it (unless a flinch happens >_>).
399 SA Timid Dialga's unboosted Draco Meteor vs Origintina with one CM: 276-326
Timid Dialga OHKOing Giratina with Draco Meteor argument is invalidated. Since Draco can do up to 73%, it won't even OHKO with 2 SR damages. I noted that you didn't mention after a CM, but then again what dragon besides Dialga can take a Draco Meteor and survive after an SR?
Well there's more than this obviously but I'll stop here for now. The boosted SA gives it a high chance of 2HKOing Kyogre and Groudon without a boost. No HP Kyogres are OHKOed by CMed Thunder after SR damage (if no Leftovers), and the same goes to no HP/SDef Mewtwo (again, if no Lefties)