0181 Ampharos

Volt Switch is the superior fast move in both damage output and energy gains, though it with an animation duration of 2 seconds (4 turns), it can be cumbersome to use. 

Thunder Punch costs the least amount of energy, and can be used frequently to either deal STAB Electric damage, or bait shields. Trailblaze has a relatively low cost, the ability to self-buff Attack, and counter-coverage against many Ground Types. Focus Blast costs the most energy, but also threatens massive damage if unshielded. Fighting-type coverage is also highly valuable. Dragon Pulse is a move limited to Community Day events, and can be chosen for its less extreme energy costs, as well as Dragon-type move coverage. Power Gem is another alternative coverage option, though it's not a particularly strong move. Thunder and Zap Cannon both demand quite a large amount of energy, and are also redundant given the high Electric-type damage output from fast moves. 

Return, while limited exclusively to Purified Ampharos, can be a functional option if you're just looking for an alright Normal-type move.

Ampharos is a mono-Electric Pokemon with below average bulk in Great League. Due to its somewhat frail bulk, Ampharos generally performs better when given both shields, as its powerful fast move can deal out significant damage over a prolonged fight. The moveset that Ampharos has makes it considerably threatening in this league, with coverage options against popular Water, Steel, and Dark-types, in addition to relatively strong neutral damage overall. Grass and Ground Pokemon are usually losing fights, and Pokemon with high damage output like those with access to Charm or Razor Leaf will easily be able to abuse Ampharos's fragility. 

Ampharos performs much better in Ultra League, with most of its struggles being Grass-types, Giratina, and Swampert. Since Ampharos is still somewhat squishy in comparison to bulkier Pokemon, it can struggle against tanks like Cresselia or Armored Mewtwo. Overall the coverage that Ampharos has is quite unique and allows it to threaten much of the meta, if not being part of the meta itself. 

Ampharos simply lacks the stats for Master League.