@ Leftovers | Natural Cure
Calm | 252 HP / 232 SpD / 24 Spe
- Giga Drain
- U-Turn / HP Ice / HP Fire
- Thunder Wave / Perish Song / Stealth Rock
What It Does:
Celebi is awesome to stop most threats that infest the metagame right now. Rain teams will have nightmares with this set, since only Tornadus-T can easily defeat it, and it must be careful not switching into T-Wave or U-Turn. Everything else just have troubles breaking its defenses. Keldeo can't do much (SE Specs Hidden Power a measly 35% chance to 2HKO with Rocks onto the field), Politoed need Specs to be threatening with Ice Beam (and you can then just go to a resistance), Jirachi can't touch it with its common moves (CM with Flash Cannon is hyper-rare, and they will get Perish Song'd anyway), and many other Rain abusers share similar situations. Even outside Rain, Celebi stops many dangerous things: Lando-I needs SR and 2 layers of Spikes to have an absymal chance to 2HKO with LO HP Ice, LO Latios needs SR to 2HKO with Draco Meteor, and Rotom-W is basically helpless as even Specs HP Ice fails to 2HKO. Celebi also has huge utility factor in Perish Song, status moves, status absorbing properties, and U-Turning capabilities.
Rotom-W and Heatran both cover the most problematic weaknesses of Celebi (Flying, Fire, and Ice) while being awesome mons themselves. Also, a Steel type can work, since Celebi is not happy to take Draco Meteors anyway, and said Steel type could use choice-locked Dragon attacks as set-up opportunities. Many other things are good with Celebi, since it usually doesn't require support, it provides support patching holes in teams and having an awesome typing in today's meta.
What Counters It:
Ferrothorn can, unfortunately, come in and start setting up as it pleases if Celebi lacks HP Fire or Rain is up. CB Scizor can destroy with U-Turn while not being OHKO'd by HP Fire, not caring much about paralysis, and being able to retain momentum whatever choice the Celebi user does.
Other things, like Volcarona, Dragonite, Gengar, Heatran and Ninetales can all threaten Celebi quite hard, although they must avoid switching into T-Wave (or the correct Hidden Power in Nite's case), or carry a Lum Berry. Also, the fact that Celebi can carry U-Turn makes it quite difficult to take advantage of, and it usually boils down to who can predict better. Even things like Skarmory can somewhat stop Celebi, since Brave Bird will do quite a number of damage, and barring HP Fire, Skarmory doesn't care about Celebi's attacks at all.
Any Additional Info:
Genesect was just banned, and this made Celebi a lot more viable. No +1 SpA / +2 Spe LO Ice Beams, and no readily available U-Turn spam can only improve my favourite pixie.