NFE SpDef WishPass (Shelgon) @ Eviolite  
Ability: Overcoat  
EVs: 252 HP / 4 Def / 252 SpD  
Careful Nature  
- Wish
- Protect
- Toxic
- Dragon Claw
Optional Move(s): 
- Brick Break
- Dragon Dance
- Fire Fang
- Outrage
- Roar
- Zen Headbutt
Optional Item(s): 
- N/A
Optional Ability: 
- N/A
Optional EV/IV(s): 
- 252 Atk / 4 SpD / 252 Spe (Jolly)
Overview: With access to Wish and a great HP stat, Shelgon makes for a solid support Pokemon for teammates which don't have access to recovery. Its amazing Defense stat also makes it a good physical wall. However, Shelgon is very passive and relies heavily on Toxic to deal damage, meaning that Poison- and Steel-types can easily switch into it. It also faces competition from Lickitung which can both pass Wish and cleanse status. 
SpDef WishPass: The combination of Wish and Protect allows for Shelgon to be an effective Wish pass user and also gives it a form of reliable recovery to remain a solid check to special threats, such as Electabuzz, Kadabra, and Magmar, throughout a game. Toxic lets Shelgon deal some chip damage to other bulky Pokemon such as Servine, Prinplup, and Staravia. Dragon Claw is a good STAB move which allows Shelgon to do some damage for its teammates and not be completely shut down by Taunt. 
Checks and Counters: Taunt users such as Monferno and Quilladin are able to stop Shelgon from passing Wish and spreading Toxic. If Shelgon is not carrying Roar, setup sweepers which don't mind Toxic, such as Pawniard, Klang, and Duosion, are all able to switch into and capitalise on Shelgon's passive nature. Poison- and Steel-types such as Roselia, Mareanie, Metang, and Ferroseed can all easily switch into Shelgon's attacks and are immune to Toxic. It also struggles to deal with Fairy-types such as Clefairy and Togetic, which are immune to Dragon Claw, and have Magic Guard and Heal Bell respectively to deal with Toxic. 
Optional EV/IV(s): An alternative spread of 252 Atk / 4 SpD / 252 Spe with a Jolly Nature can be used for the Dragon Dance, Outrage, Fire Fang, and Zen Headbutt set and plays off the opponent expecting the WishPass set. It lets Shelgon be a decent cleaner. Whilst Shelgon does have an easier time setting up due to its better bulk, when compared to other Dragon Dance users such as Fraxure and Hakamo-o, it lacks the coverage to hit Fairy-types hard and its poor speed means it needs to set up minimum two Dragon Dance in order to outspeed the entire unboosted metagame.