Harry Dex!
This chapter is informative about Harry's Pokémon shown or mentioned so far.
Dragon Pokémon:
GARCHOMP, Mach Pokémon, Dragon/Ground types.
Ability: Rough Skin. Causes enemy physical attacks to deal recoil damage.
ALTARIA, Humming Pokémon, Dragon/Flying types.
Ability: Natural Healing. Status conditions such as Paralysis, Poison, Sleep, Freeze, or Burns are cured when the Pokémon returns to its Poké Ball.
Fairy Pokémon:
SYLVEON, Entwined Pokémon, Fairy type.
Ability: Pixelate. Causes Normal-type moves to become Fairy-type and adds a 20% power boost. So Hyper Beam, 150 power points of damage, becomes Fairy-type and deals 180 power points.
RIBOMBEE, Flying Bee Pokémon, Fairy/Bug types.
Ability: Dust Shield. Protects the Pokémon from additional effects from attacks, such as ice attacks that can cause freezing, or fire attacks that cause burning.
TOGEKISS, Jubilation Pokémon, Fairy/Flying types.
Ability: Super Luck. The Pokémon is so lucky that its critical hit rates increase dramatically.
GARDEVOIR, Hug Pokémon, Fairy/Psychic types.
Ability: Synchronize. Status effects inflicted on Gardevoir are inflicted on the opposing Pokémon as well.
SLURPUFF, Meringue Pokémon, Fairy type.
Ability: Sweet Veil. Prevents the Pokémon and its allies from falling asleep.
Steel Pokémon:
AGGRON, Iron Armor Pokémon, Steel/Rock types.
Ability: Iron Head. Prevents recoil damage from moves used.
METAGROSS, Iron Leg Pokémon, Steel/Psychic types.
Ability: Light Metal. Halves the Pokémon's weight.
SANDSLASH (ALOLA VARIANT), Porcupine Pokémon, Steel/Ice types.
Ability: Snow Coat. Increases the Pokémon's evasion in snow or snowy weather.