Decidueye Hisuian Form's Weaknesses

Best Counters

Decidueye Hisuian Form is especially weak against Flying type Pokemon, they will deal 4x damage to it!

The types that are strong against Decidueye Hisuian Form are Flying, Fairy, Fire, Poison, Psychic type Pokemon.

For the best defense, Flying, Poison, Bug types have very effective defense against Decidueye Hisuian Form, and will be resistant to damage from Decidueye Hisuian Form's STAB attacks:

Ice types will also deal super-effective damage against Decidueye Hisuian Form, but be careful using Pokemon of this type because they may also receive extra damage from some of Decidueye Hisuian Form's attacks!

Weaknesses

Decidueye Hisuian Form's type is Grass and Fighting.

Decidueye Hisuian Form is especially vulnerable to Flying attacks, it will receive a super effective four times (4x) the amount of damage! Since Flying type Pokemon are especially strong against Decidueye Hisuian Form, you should attack with this type of Pokemon.

Decidueye Hisuian Form has a weakness to Flying, Fairy, Fire, Ice, Poison, Psychic types. These Pokemon types will be strong against Decidueye Hisuian Form, causing Decidueye Hisuian Form to take a super effective quadruple (4x) damage from Flying type attacks, and causing Decidueye Hisuian Form to take a super effective double (2x) damage from Fairy, Fire, Ice, Poison, Psychic type attacks.

Please keep in mind that Decidueye Hisuian Form is resistant to attacks from Dark, Electric, Grass, Ground, Rock, Water types, and these attacks are not very effective and cause reduced damage, so they should be avoided.