702 Dedenne

Thunder Shock offers very high energy generation, with low damage output despite benefiting from STAB. Tackle is a poor move and can't be Super Effective against anything. 

Dedenne only has two Charge Moves available, and therefore those are its only options. Discharge costs a moderate amount of energy and provides STAB Electric-type coverage, while Play Rough demands more energy and hits harder with Fairy-type coverage. 

Dedenne sports an interesting and relatively unique Electric/Fairy typing, which on paper isn't particularly synergistic. However, its typing does let it stand out among other Pokemon with similar typings, giving it a niche in specific PvP formats. Dedenne sports average bulk in this league, and heavily relies on its Charge Moves to deal damage. Because of the inefficiency in its moveset due to the lack of damage from its Fast Move and its cheapest Charge Move requiring 45 energy, it is more likely to deal overkill damage when finishing off an opponent, or come out slightly short of what's necessary to win a matchup. Therefore Dedenne will appreciate any advantage it can get, be it an aggressive or greedy farm, or shield or HP advantage. Due to the high energy cost of Play Rough, Dedenne tends to struggle heavily against any popular Ground or Grass Pokemon. 

With a max CP of 2081 at level 50, Dedenne would appreciate more stats for Ultra League. 

It's true, Fairy Pokemon tend to do well against Dragon-types which are very common in Master League. But stats still matter.