Gardevoir ex

This deck is focused on using baby Pokémon, which in this deck are so strong that it looks like they are exes, they are:

Drifloon: To deal a lot of damage, you need to have a lot of basic psychic energy in the disposal and Gardevoir ex to power it, but the focus is not on powering, but on the damage counter. Drifloon attacks 30x with each counter on it and to make it stronger, get a Bravery Charm to give it more HP and be able to put more damage counters to give even greater damage.

Scream

This deck is focused on using baby Pokémon, which in this deck are so strong that it looks like they are exes, they are:

Drifloon: To deal a lot of damage, you need to have a lot of basic psychic energy in the disposal and Gardevoir ex to power it, but the focus is not on powering, but on the damage counter. Drifloon attacks 30x with each counter on it and to make it stronger, get a Bravery Charm to give it more HP and be able to put more damage counters to give even greater damage.

Scream Tail: This Pokémon is a bit similar to Drifloon, but instead of attacking your opponent's active Pokémon, it attacks 20x every damage counter on it to any of your opponent's Pokémon, to knock out that Pokémon your opponent is preparing. I recommend you use the Ancient Booster Energy Capsule more to give +60 HP, as it is an Ancient Pokémon.

Cresselia: If you have a lot of Pokémon with a lot of damage counter, I recommend using Cresselia, which casts 2 counters from each of your Pokémon (even yourself) on 1 of your opponent's Pokémon, as if it were a situational Scream Tail.

Munkidori: You use it to knock out one of your opponent's Pokémon that has 30HP remaining, but it needs to have basic dark energy in it to be able to use its ability. You energize 2 basic psychic energies on it through Gardevoir ex to have 4 damage counters and move up to 3 damage counters on it to any 1 of your opponent's Pokémon.

The objective of the deck is to discard basic psychic energy and evolve your Ralts into Kirlia to be prepared to evolve into Gardevoir (that's why this deck doesn't use Rare Candy, because Kirlia is like a Radiant Greninja) and attack with your Baby Pokémon (Drifloon and Scream Tail).

Note: The deck was based on the modification of the Battle League Deck (the link) but it is in Portuguese and is a cheaper version, as it does not have Ace Spec.