I guess I'll start by saying that I've lurked a fairly huge amount here, and I based the idea here around Entei (and finding a way to complement its newly gained Sacred Fire), and I thought it was cool enough to post. That said, I'm not entirely sure if Zapdos is the right second for it (maybe Galvantula? Mandibuzz? idk), or if it's now considered outclassed by Mega Charizard, so feel free to pick this apart or suggest an alternative; I just wanted to put the idea out. Now, I don't necessarily think it's the worst thing in the world if a different core ends up working better with the eventual CAP; there's quite a bit of variation in the Gen VI meta, and I personally doubt that it's realistic to expect anything created to fit one core and only that one core. Entei - #132 in OU, #95 in Suspect, B- in Viability Rankings Zapdos - #82 in OU, #47 in Suspect, B+ in Viability Rankings Why these Pokemon: What Entei does: Basically just throw Sacred Fire at things, which is kind of a lot. The raw power of Sacred Fire backed up by its burn rate is pretty scary to switch into; when played right, it's very disruptive, between the damage output putting holes in things and the burn rate threatening to neuter physical attackers. Besides that, it's got pretty decent stats all around, access to priority in Extremespeed, and pseudo-QuakEdge in Bulldoze/Stone Edge (the former of which annoyingly doesn't OHKO Heatran unless it's Banded). It's a bit of a one-trick doge, though, and isn't overly threatening to Pokemon that can take the hit and don't care about Burn. That's pink blobs, as well as bulkier Fire-types and special attackers. What Zapdos does: Serves as a special defensive check, marked by its access to Roost, Defog, and hard-hitting Thunderbolts, while packing Heat Wave to send Steels scurrying. Zapdos stands (err, soars) in an odd halfway point between offensive mashing and defensive getting-mashed; its bolt isn't as strong as Thundurus's, but it's got more offensive presence than something like a Mandibuzz or a Celebi. Like Entei, it's got a legendary 580 BST, which lets it achieve this kind of balance without sacrificing something like Speed. However, it doesn't deal too well with non-Steel Stealth Rockers, and said Sneaky Pebbles will whittle away at its HP. Set-up sweepers can break through it, while it doesn't quite have the firepower to break through special walls. What Entei does for Zapdos: Zapdos enjoys having physical attackers burned, being a Pokemon primarily used as a special wall; with physical mons incapacitated, it's easier for special walls to focus on special walling. Other things Zapdos dislikes include burns and Ice moves, both of which make its life difficult, and both of which Entei can take without too much worry. What Zapdos does for Entei: Throws T-bolts at the Water-types that would otherwise tank Entei's Sacred Fires, which frees up Entei to spam its sole STAB move. Zapdos also takes paralysis and Earthquakes like a champ, which would otherwise impede Entei's offensive and not-getting-KO'd capabilities, respectively. Finally, Zapdos is a Defogger, and it can remove those pesky Sneaky Pebbles and Garden Rakes that would otherwise hurt Entei's sensitive paws. Why do these Pokemon not form an effective core right now? What possibilities could a third Pokemon provide that improves the core significantly, which aren't currently provided by OU Pokemon? As is, Entei and Zapdos do have some shared weaknesses that warrant the creation of a Major Third/Major Triad. Pink blobs have the defensive bulk to not care about Entei's Sacred Fire, and have Natural Cure to heal any burns, while Zapdos is even more helpless in their fat faces. Dragons are another bugbear; they too resist the STABs of both legends, and a good deal of them aren't threatened at all by the prospect of a burn; as such, they can set up easily and proceed to wreck the core. Both members of the core greatly dislike the idea of getting slapped with a Toxic, which gives them a turn counter and greatly hampers their ability to tank; Heatran is a particular example, which isn't overly scared by either Pokemon. Rotom-Wash isn't exactly an ideal opponent, either, and can proceed to dish out major damage with its Hydro Pump. The core does okay against Rock-types and can handle Stealth Rock decently with Zapdos's Defog, but some backup might be nice to have. The two Pokemon aren't capable of taking OU by storm as is, but they're not entirely useless either. They both do a rather stand-up job of demolishing most Steel-types via their Fire-type coverage, and everything they provide to each other would also be provided to the final CAP; this means that the third Pokemon would be able to take advantage of burned targets, Extremespeed support, hazard removal support, sponges for burn and paralysis, an Earthquake sponge, and just generally tankish coremates to aid it in either cleaning up the mess of the opponent's team or tipping it into a mess where Entei or Zapdos can clean up. tl;dr To conclude, support Entei + Zapdos, because they're mons that work kinda well in OU so far and fulfill unique roles, but could use an 3rd mon nudge in the core direction to cover stuff they both have trouble with. This core seems to fit the other guidelines suggested in this thread (no M-Evos, some degree of synergy, goldilocks zone of viability alone and separately, switching capabilities, etc). If that doesn't sound thorough, read the actual thing.