As many people have already pointed out, our core really needs to focus on Lucario's unique traits, or else it could easily end up working better with a different attacker. As such, I will be covering mainly Lucario in this post, and what exactly could give him the edge during team building 1. Typing Synergy On paper, Lucario has outstanding synergy with Latias between their somewhat unique typings, each covering the other’s weaknesses almost perfectly, and one could think that this alone gives him an immense advantage when competing for a team slot. In practice, however, Lucario has a hard time putting this to any good use. With his extreme frailty, Lucario won’t be contributing much defensively anytime soon, being worn down quickly by even resisted moves, and in his role as set-up sweeper, he dislikes coming in too often in order to threaten the opponent offensively. Frail sweepers generally only get one chance to set up, so they just can’t risk losing health by pivoting around and covering their team’s weaknesses. For most part, our core would have to operate without Lucario’s support, making that great typing synergy go largely unused. So why use Lucario as your set-up sweeper instead of something like Mega-Pinsir who can do the same job much more reliably? Mega-Pinsir might have difficulties with certain threats that Lucario can take out, such as Rotom-W and Skarmory, but there are just so few of those that this issue can easily be redeemed by appropriate team support, in order to enjoy the otherwise far greater benefits of using Mega-Pinsir. Besides, even a core utilizing Lucario as its sweeper would have to employ additional preparation against those threats, as on his own Lucario can by no means counter or even check them. My point is this: Lucario really has to take advantage of his typing synergy in order to not be outclassed, and as a pure set-up sweeper he just can’t do that. Sweeping will always be Lucario’s main function, but the core has to support him in a way that allows him to take up roles outside of that. Providing Lucario with frequent switch in opportunities (slow U-Turn, dual screens) and extending his longevity (Wish, Heal Bell, Healing Wish) would allow him to be a much more active and integral component of the core even before he attempts the sweep. If Lucario manages to function reliably throughout the entire match, opposed to being a one-time-use Pokémon, he could finally take advantage of that great typing synergy by pressuring many Latias counters actively, something not many other sweepers can claim to do. 2. Versatility Lucario possesses an extremely wide range of attacking options, to the extent where he can take out basically anything with just one turn of set up and the appropriate move. Even when we focus on only the physical attacking sets, his versatility lets him stand out from many of his competitors. Between Close Combat, ExtremeSpeed, Earthquake, Ice Punch, Iron Tail, and Crunch, or even Stone Edge, Bullet Punch, and Blaze Kick, the opponent will be hard pressed to find a safe switch in. Unfortunately for Lucario, he can’t run all those options on one set, forcing him to let certain Pokémon counter him no matter what. Still, the ability to threaten the majority of the metagame is a great asset when using Lucario, and will definitely have to be taken into account when building our core. Lucario will be generally running Sword Dance, Close Combat, ExtremeSpeed, and a coverage move that takes care of fighting resists (mostly Earthquake, Ice Punch or Iron Tail). In my opinion, we should aim to have multiple similarly viable options for the last slot, so Lucario can freely choose which coverage move he wants to go with, retaining much of his unpredictability. A good way to achieve this is to give our CAP a similar movepool, enabling it to cover whichever Pokémon Lucario misses out on, but preventing it from dealing with all of them on its own. Both, CAP and Lucario would complement each other with their moves, but the ability to actually choose who of them covers what makes them much harder to predict and counter. Also, this is a nice way to bind Lucario to our core, as no other Pokémon could work in the same way with our CAP. 3. Late game potential Few Pokémon are as reliable as Lucario when it comes to late game sweeping. This potential comes largely from his access to the prized ExtremeSpeed, a move that makes him notoriously hard to revenge kill once the opposing team is sufficiently weakened. Common priority users, such as Talonflame, Mega-Pinsir and even CB Dragonite, all have to tank one ExtremeSpeed, most likely backed up by a Sword Dance boost, before even being able to move. Also, Lucario is one of the few sweepers who aren’t completely stopped by paralysis. I would say that this is the main advantage Lucario has over Terrakion, who otherwise has a very similar role, and the typing to potentially fit into our core. In order to make the most out of this advantage, our core has to ensure that Lucario can consistently set up a late game sweep in the first place. Latias’s Healing Wish is perfect for this purpose, not only recovering any damage Lucario might have taken earlier on, but also providing him with a free switch in and probably a good typing match up. If Healing Wish was used on a choiced Pursuit user, Lucario would basically get a free set-up turn, too, something the opponent always has to be wary of. On the other hand, the CAP could guide Lucario’s sweep by weakening the opposing team sufficiently, either by laying down entry hazards, or by acting as a wall-breaker.