Golem

Golem is a powerful Sturdy user in 1v1. Its STAB EdgeQuake has good coverage and lets it beat commonly used Pokemon like Mega Charizard X and Zeraora. Golem also has the ability to viably utilize Z-Moves for both of its STAB attacks, which, depending on the Z-Crystal used, lets it beat non-Magnet Rise Mega Metagross and Air Balloon Heatran. Its access to priority in Sucker Punch also gives it the potential to beat bulky Pokemon like Meloetta and Genesect that would be able to take just a Z-Move. In addition to all this, it has access to moves like Rock Blast and Counter, which can help it defeat Pokemon like Jumpluff and Choice Scarf Landorus-T, respectively, which would otherwise beat it. Unfortunately, Golem's pitiful Speed tier leaves it outsped by the majority of the metagame and vulnerable to faster bulky Pokemon like Serperior and Tapu Lele. Another factor that severely affects its viability is the ubiquity of Mold Breaker, Fake Out, and Skill Link Pokemon like Mega Gyarados, Mega Lopunny, and Mega Heracross, which can bypass Sturdy. These downsides make Golem face competition for its niche from Donphan, another Sturdy user that also has access to Ground-type STAB and priority.