Substitute is a Light type move that replaces the user with a statue in order to avoid damage from the opponent.
This statue has 25% of the total HP of the ponymon who has used the attack and it takes 25% of the total health of the ponymon. If the user has less than 25% of health the move will fail. If the substitute loses all it's Hp it's destroyed.
Ponies that learn this move:
"The user creates a decoy using one-quarter of it's full HP."
Disclaimer: More ponies may need to be added with more expansions.