Alright, I'm not going to say whether or not I think Giratina is broken before I get to mess around with it on the suspect ladder, so I'd like to get some discussion going on what exactly Giratina's best sets are. Personally, I think any sets using Rest + Sleep Talk, like Cro and Defensive are just trash. They're slow and passive, not to mention they give up a ton of free turns. Without actually investing into its attacking stats, Tina is pretty weak, and having basically 0 coverage to give all the Fairies and Dark's that are looking to take advantage of Tina free switch-ins just isn't good.
The sets I actually do think are good are the sets based around using Dragon Tail to shuffle shit. Tina's Dragon Tail hits really fucking hard on neutral targets when it's invested, in addition to racking up hazard damage. These sets play out somewhat similarly to bulky SR Garchomp, but they need something else to set up hazards for them, which actually makes me question the use of Defog on them. The basic skeleton's I've made look like this.
Giratina-Origin @ Griseous Orb
Ability: Levitate
EVs: 64 HP / 252 Atk / 4 Def / 188 Spe OR 144 HP / 252 Atk / 112 Spe
Adamant Nature
- Dragon Tail
- Iron Tail/Shadow Force
- Earthquake/Aura Sphere
- Shadow Sneak/Defog/Thunder Wave/Toxic/Outrage/Will-O-Wisp
I apologize for this being a mess of slashes, I haven't had a chance to test this yet, so it's more than a bit rough around the edges. The EVs are fairly simple, the first spread outspeeds Jolly Bisharp and anything slower, while giving you a lot of attack to hit hard, the downside of this is having very little EVs left to invest in bulk. The second spread is a lot bulkier, but only outspeeds Jolly Tyranitar. For the moves, Dragon Tail is the standard move that you want to spam most of the time. It hits any neutral target incredibly hard, racks up hazards damage, and prevents the opponent from gaining any footing. The second slot is basically what I'm doing to avoid being fucked by Fairies that don't care about Dragon Tail. Iron Tail hits fairies and Ttar for just enough, with an 85% chance to 2HKO Max/Max Clefable. If you can predict the switch into a Fairy (which is honestly pretty easy most of the time) you can basically chunk it for most of its HP, or if its a Diancie or a Gardevoir straight up remove it. The downside of Iron Tail of course is that its inaccurate, and does very little to Azumarill and Klefki. Shadow Force hits incredibly hard with the given EVs, but leaves you walled by Clefable who can just stall you out with Soft-Boiled, and has similar issues with Roost Mega Altaria. The next slot is everything I can think of to avoid being screwed by Bisharp, and Ttar if you didn't opt for Iron Tail. EQ does about 85-95% with the given attack investment, but sadly will never OHKO. The perk of it I suppose is completely smashing things like Heatran. Aura Sphere OHKOs Bisharp, but with 0- SpA hits everything else really weakly. The last slot is basically me listing off everything else that can be helpful, as the three things I've discussed above hit everything you need to do. Shadow Sneak gives you general priority that still manages to hit decently hard, and more importantly smacks Gengar, the Lati twins, and Gardevoir. Defog is kind of self explanatory, you beat nearly every SR setter so Tina uses the move pretty well, but it also removes your own hazards that help when spamming Dragon Tail. Thunder Wave cripples things on the switch, and really rounds Giratina out against offense, Toxic is like a Thunder Wave for bulky teams, crippling things like Mandibuzz and Chesnaught that otherwise love to come in on Tina. Outrage hits just as hard as Shadow Force does, and since this Tina can lure in Fairies can be used to clean late game, finally Wisp can spread burn which can help to wear down the bulky teams and cripple physical attackers.