Manaphy
Manaphy has access to Tail Glow, cranking its Special Attack up by 3 stages, as well as Rain Dance, making it an extremely powerful attacker capable of ripping opponents apart with spammable, hard-to-avoid bubbles. Manaphy also has decent bulk, allowing it to tank attacks such as PsyConversion Porygon-Z's Psybeam, Rayquaza's Dragon Pulse, and Marshadow's Thunder Punch. Additionally, it can surprise enemies with a more defensive approach thanks to its access to Acid Armor, giving it the bulk to survive powerful physical hits like Rayquaza's boosted Crunch and Mega Lucario's boosted Extreme Speed. However, Manaphy's defensive typing, while useful, leaves it weak to Grass and Electric, meaning Pokémon like EleConversion Porygon-Z, Bellossom, and Zekrom are easily capable of KOing it with powerful STAB moves like Discharge, Giga Drain, and Thunder Fang, respectively. Additionally, Manaphy has a hard time breaking through specific specially-bulky Pokémon, namely those that resist its STAB moves like Bellossom, Slowbro, and Kyogre. Finally, Manaphy's Speed is only average, meaning faster Pokémon can take care of it if they can survive the barrage of bubbles. This is the one bubble-blowing baby that every able-bodied patron in the bar doesn't want to beat senseless.

TAIL GLOW
Move 1: Tail Glow
Move 2: Rain Dance/Acid Armor
Move 3: Bubble Beam
Move 4: Bubble
Item: Splash Plate
Nature: Modest/Timid/Calm/Bold
Ability: N/A
Tail Glow gives Manaphy an intense boost to its offensive prowess very quickly by giving it a Special Attack increase of +3. Rain Dance further boosts Manaphy's STAB moves, allowing them to quickly dispose of Pokémon that resist them. Acid Armor can be run over Rain Dance to sacrifice power for physical bulk. Bubble Beam is difficult to avoid, especially at choke points, and can make quick work of most of the metagame after a few boosts. Bubble is weaker and harder to land, but provides more projectiles to ruin an opponent's day with.