Jolteon (Offensive)
With blistering Speed and excellent Special Attack, Jolteon is an incredibly potent threat in DPP OU. Jolteon can make great use of Choice Specs thanks to its nearly unmatched Speed, allowing it to fire off powerful Thunderbolts in a tier where teams often forgo utilizing sturdy Electric-type resistances. Despite Jolteon's somewhat scarce movepool, it gets phenomenal auxiliary coverage with Hidden Power Ice or Hidden Power Grass to smack around Ground-types that are immune to Thunderbolt. Jolteon can also utilize Shadow Ball or Signal Beam for additional coverage, and they're useful for the omnipresent Celebi if Jolteon is running Hidden Power Grass. Choice Specs Jolteon often uses Baton Pass as its final move to help scout its incoming counters at the beginning of games, such as the aforementioned Ground-types or defensive behemoths like Blissey. If Choice Specs isn't your preference, Jolteon can also use Life Orb effectively for the boost in power and ability to switch attacks, while the recoil can often be mitigated by Volt Absorb. Though less frequently seen, Charge Beam or Substitute + Baton Pass sets are great choices for Jolteon to attempt a sweep and support the team, respectively.
Shaymin (Offensive)
Don't let its undeniably endearing appearance fool you; Shaymin can be a very dangerous Pokemon in the right hands. This cute little hedgehog is usually seen terrorizing teams with offensive sets that utilize its signature move, Seed Flare. This powerful attack is what differentiates Shaymin from its fellow Grass-type brethren, and with an unbelievable 40% chance of reducing its opponent's Special Defense by two stages, it can be a very daunting attack to switch into. Unfortunately, Grass doesn't have the greatest offensive coverage, but Shaymin can make up for this shortcoming with the appropriate Hidden Power. While Hidden Power Fire will smack around Scizor, Forretress, and Skarmory, Hidden Power Ice is equally useful to nail Dragonite and other Flying-types. In addition, Earth Power gives Shaymin a means of defeating Fire-types like Heatran and Infernape. Shaymin doesn't really have many other options, but it can use either Leech Seed or Rest in the final slot of offensive sets to increase longevity, and the latter is especially useful on Shaymin thanks to its ability, Natural Cure. Although Shaymin is almost exclusively used as a Life Orb or Leftovers user, it can make good use of either Choice Scarf or Choice Specs for a nice element of surprise.
Zapdos (Offensive)
While most people rave at Zapdos's incredible defensive typing and great overall stats, many forget that it packs a monstrous base 125 Special Attack and that Electric is one the best offensive typings in DPP OU. With a Life Orb attached, Zapdos epitomizes what it means to be a 'bulky attacker', as it can fire off powerful, boosted attacks while shrugging off a variety of hits with Roost. Thunderbolt is a given on all sets, while Zapdos gets almost all the coverage it needs between Heat Wave and Hidden Power Grass. Agility can be used en lieu of Roost to transform Zapdos into a fearsome late-game sweeper, and Hidden Power Ice is generally given the nod in this case since Zapdos can outspeed Choice Scarf Flygon after an Agility. Choice Specs Zapdos is also an effective anti-lead when paired with Hidden Power Flying to OHKO Machamp, as Zapdos can 2HKO nearly every lead while it has the bulk to avoid being OHKOed by most Pokemon in the lead position.