Sub 3 Attacks (Elekid) @ Leftovers
Ability: Static  
EVs: 252 SpA / 4 SpD / 252 Spe  
Timid Nature
IVs: 2 Atk / 30 SpA  
- Thunderbolt  
- Hidden Power [Grass]  
- Fire Punch 
- Substitute 
Optional Move(s): 
- Cross Chop
- Psychic
- Quick Attack
Optional Item(s): 
- Lum Berry
Optional Ability: 
- N/A
Optional EV/IV(s): 
- 4 Atk / 252 SpA / 252 Spe (Hasty Nature)
Overview: Elekid shines as the third fastest unboosted Pokémon in the metagame, only outsped by Luvdisc and Voltorb. It boasts a colorful movepool, and together with its respectable base 63 Attack and 65 Special Attack, make it a potent offensive check to many highly ranked Pokémon in the tier, namely Rhyhorn, Delibird, Seaking, Dustox, Pidgeotto, Taillow, Butterfree, and Staryu. 
Sub 3 Attacks: Thunderbolt, Fire Punch, and Hidden Power [Grass] is enough coverage to hit everything in the metagame for super effective or neutral damage. Substitute lets Elekid capitalize on the switches it forces against the aforementioned Pokémon, allowing it to potentially get a safe 2hko on the opponent and to avoid being hit with status moves like Toxic, Sleep Powder, Stun Spore, and Thunder Wave from bulkier Pokémon expecting to live a hit. 
Other Options: Quick Attack is an option over Substitute that lets you pick off weakened foes, particularly Delibird, Pidgeotto, and Taillow looking to knock you out first with Quick Attack of their own, often bolstered by Choice Band. Cross Chop is Elekid’s strongest move to hit specially defensive Delcatty and Lileep and both S-Rank Normal-type Aipom and Castform, although only marginally so against the latter two. Lastly, Psychic is your strongest non-STAB special attack, letting you chunk bulky Poison-types like Dustox and Koffing, but it is generally outclassed by its other coverage options. On variants running a fourth attack, Lum Berry can be used to cure status that you cannot avoid by setting up Substitute. 
Checks and Counters: Despite having a wide variety of coverage options, Elekid can still struggle versus a handful of answers in the tier. Specially defensive Pokémon such as Lileep, Bayleef, Dustox, Delcatty, and Grimer can take any special hit with ease and retaliate with attacks of their own, threaten it with status like Toxic or paralysis from Body Slam, and even heal up.