Ferrothorn

Ferrothorn is one of the sturdiest walls in the metagame, checking many offensive threats such as Kyogre, Xerneas, Zekrom, and Zygarde, depending on its set. Its fantastic defensive typing gives it multiple resistances to common coverage moves while having minimal weaknesses. Iron Barbs increases the passive damage it dishes out, punishing common contact moves like Sunsteel Strike and U-turn. Its immunity to Leech Seed and Toxic keeps its longevity high. It has great utility moves such as Spikes, Leech Seed, and Knock Off, slowly but effectively chipping down more offensive Pokemon. Spikes, in particular, greatly improves a team's entry hazard game and long-term pressure, especially when paired with ways to shut down Defog such as Taunt Yveltal. This moveset, while effective in its role, is fairly passive overall, though, so certain strong walls such as Ho-Oh, Corviknight, and Eternatus have minimal issues threatening it without taking much damage.