468 Togekiss

Charm enables Togekiss to deal huge STAB Fairy-type damage without relying on its charge move, though it energy gains are terrible. Air Slash also gets STAB, but is more of a niche since there's many other Flying-type Pokemon.

Ancient Power and Aerial Ace both cost the same 45 energy, the former offering good coverage and the latter benefiting from STAB.  Flamethrower could be used to cover against Ice and Steel-types, and is necessary to avoid being completely walled by the latter.  Dazzling Gleam can be used to land a surprise huge hit against unsuspecting Kyogre or Giratina-O, although Charm's damage is often enough on its own.

The addition of Charm thanks to the July 2019 move rebalance enables Togekiss to become an anti-meta specialist, as its greater ATK stat limits its bulk, and a Fairy/Flying typing can be vulnerable to common threats. The extremely poor energy generation from Charm also prevents Togekiss from applying any sort of significant shield pressure, which may somewhat discourage its use. As an anti-meta pick, popular Pokemon that are weak to Fairy-type attacks like Medicham, Sableye, Altaria, and Umbreon become easy prey for Togekiss. Unfortunately the prevalence of Steel-types in the meta does hold Togekiss back quite a bit, which makes Pokemon like Medicham a good choice to compliment Togekiss. Overall still a considerable choice, though other Fairy-types like Wigglytuff might fulfill the role a bit better depending on the format. 

The prevalence of Giratina in this league makes Togekiss stand out as an excellent counter to them, and also some of the Dark and Fighting-types that are also present in the meta. Just like in Great League, Togekiss still has to be cautious of common Steel-type Pokemon in this league, in addition to less favorable matchups against Lapras and Snorlax. The lack of bulk and slow energy gains however, prevents Togekiss from winning more matches against neutral opponents like Cresselia. 

Master League is often dominated by Dragon-types, and is the perfect place for Togekiss to feast. Although it does not possess the greatest stats, Togekiss's sheer type advantage carries it through many Dark- and Dragon-type matchups. Not even the part Steel-type Dialga is safe from Togekiss, as Togekiss can win the match up by committing to both shields. The extra Ground-type resistance provided by its Flying-type is also helpful for taking on Groudon.

Without the sheer advantage from its typing, Togekiss's below average stats becomes a noticeable weakness. Pokemon with great neutral damage, such as Mewtwo and Kyogre, can easily overwhelm it. Steel-type Pokemon are extremely difficult to get around due to how long it takes for Togekiss to reach Flamethrower. In order to use Togekiss effectively, it must be paired with strong Steel-type killers, or a way to bait Steel-types out and destroy them before Togekiss enters the battlefield. Togekiss also requires shields to be saved for it, as it is otherwise vulnerable to hard hitting coverage attacks from the likes of Dialga or Zekrom.