Kyurem

Kyurem is a decent wallbreaker against balance teams thanks to its high Special Attack and fantastic Ice- + Ground-type coverage, which hits a majority of the metagame hard and forces a lot of switches. Its bulk and resistances are also excellent, letting it easily set up Substitute on common defensive Pokemon like Tentacruel, Rotom-W, Politoed lacking Encore, and Ferrothorn lacking Gyro Ball. It can also take a hit from other Pokemon like Starmie and Heatran. Kyurem's Speed tier lets it outpace some offensive Pokemon, like Dragonite, Excadrill, Breloom, and Heatran. However, it's outsped by Pokemon like Keldeo, Garchomp, Latios, and Alakazam, all of which are incredibly common and hit it super effectively. Kyurem is also reliant on having Substitute up to wallbreak properly, as it's otherwise forced out or crippled by Pokemon like Jellicent, Heatran, and Politoed. By extension, it must be careful when coming in on these bulky Pokemon. It can also struggle to break through bulky offensive threats that threaten it, like Tyranitar, Reuniclus, and Volcarona. Kyurem is very vulnerable to residual damage due to not healing with Leftovers in sand and being weak to Stealth Rock, forcing it to spend turns using Roost instead of attacking. Kyurem also faces competition as a Dragon-type wallbreaker from Pokemon like Latios, Dragonite, and especially Kyurem-B, due to them more easily fitting on teams, relying less on setup to wallbreak, and having more defensive utility.