Rhydon

Rhydon is a high-risk yet high-reward Pokemon that takes a more offensive lean as a Rock-type and Stealth Rock setter over Regirock. First, its secondary Ground typing gives it a great matchup against Regirock, while its sheer power and coverage pressure Slowking and Grass-types trying to switch in. This also gives it an Electric immunity against Pokemon like Magneton, Manectric, and Ampharos to pivot around them or take advantage of Choice-locked moves. Second, Rhydon has Swords Dance to break past defensive cores and threaten to sweep. Third and finally, its access to Rock Blast is a unique tool over Regirock, which lets it adequately check SubToxic Charizard and SubCM Drifblim. All of these traits make Rhydon a good wallbreaker on aggressive teams that has a good matchup against Regirock + Slowking cores while sharing a few of Regirock's defensive responsibilities against Tauros and Skuntank.

However, most of Regirock's splashability in DPP NU comes from its defensive traits, and Rhydon lacks Regirock's mixed bulk and has a 4x weakness to Water- and Grass-type moves, making it worse against Tauros and offensive Fire-types without the ability to tank against Water- and Grass-types such as Floatzel, Vileplume, and Cacturne to respond with Thunder Wave or Explosion like Regirock. Rhydon's worse defensive profile, reliance on coverage options that can miss, and need for specific items in specific circumstamces can all make it inconsistent. Rhydon also shares competition with other Ground-types that have massive offensive potential, such as Swords Dance Sandslash, Marowak, and Piloswine.