Orthworm the Titan
Orthworm @ Leftovers/Chesto Berry
Ability: Earth Eater
Tera Type: Electric
EVs: 252 HP / 252 Atk / 4 Spe
Adamant Nature
- Coil
- Iron Tail
- Body Press/Earthquake/Tera Blast
- Shed Tail/Rest/Smack Down/Rock Slide
Ever since Orthworm's magnificent introduction when we first stumbled upon him as a Titan, I have been a fan. This is a fun and flexible set that takes advantage of the accuracy boost from Coil and uses Orthworm as an offensive tank. First, Tera Electric + Earth Eater means that he has no Type weaknesses, and this advantage can't be taken away by Smack Down, i.e. Eelectross.
EV distribution and Nature maxes bulk and power, since his Def will be getting plenty thicc with Coil. 4 EVs in Speed to out-speed other slow mons who put their Nature and EVs elsewhere. Either Leftovers if you want continuous healing over time while you stack Coils and bodies, or Chesto Berry if you want to pair it with Rest for 1 big heal.
Now then, the main offensive selling point of this set is Coil + Iron Tail. One Coil raises Iron Tail's accuracy to 100, so now he can reliably use a 100 BP STAB move with a respectable 30% chance to lower Def. The rest of the kit depends on how exactly you want to utilize Orthworm on your team. You can use Body Press to fully take advantage of Orthworm's huge Def stat, augmented by Coil boosting his Atk and Def. Steel + Fighting is a type combo that has no single type resistances, so complete SE/Neutral coverage. Though the SE coverage does overlap significantly. Alternatively, Tera Blast to potentially take advantage of your tera type, or EQ for obvious coverage options.
His 4th move really lets you lean into how exactly you want Orthworm to work for your team. Shed Tail if you have a bad match up, and want to pivot and set up a teammate for success. Then you can switch Orthworm back in for a heal if you predict an impending Earth attack. Rest + Chesto for staying power as mentioned earlier. Or if you just go full offense, and you choose EQ for your third move, you can pair it with Smack Down for a strong "EdgeQuake" 1-2 punch, with SD still doing solid damage after a couple Coils. This combo can deal with what would otherwise be a potential threat like Kilowattrel. Ordinarily, Kilo's SpA and Steel res would be a threat to Orthworm, but going Tera Electric gives him resistance to Kilo's usual STABs, Thunder and Hurricane. SD knocks it out of the air, and if that somehow doesn't also OHKO it, a now super effective EQ will. Also works for other pesky birds like Corviknight and Skarmory. There's something satisfying about the humble worm getting sweet revenge against those pesky birds. You can also just use Rock Slide for a higher BP stand-alone "EdgeQuake" coverage option with a flinch chance, that also has its accuracy issues fixed by Coil. If only he got Stone Edge.
Let me know if anyone has any thoughts or suggestions.