Meganium/Feraligatr δ

Overview

This deck attacks with Meganium δ or Feraligatr δ, two bulky Stage 2s that are capable of utilizing Double Rainbow Energy. Meganium lets you get set up with its Evolutionary Call Poké-Power, and Feraligatr's Battle Aura increases your damage output, eliminating the drawback of Double Rainbow Energy and letting it function as pseudo-Energy acceleration.

Ideal Gameplan

There are two main ways of setting up: first is getting Holon's Castform out and Delta Drawing into more cards, and second is turboing out a fast Meganium and using Evolutionary Call to search for Pokémon to put on your Bench. Leading with Castform or Chikorita is ideal, as Castform needs to be Active to attack, and Chikorita has a Sleep-inducing move to buy time.

Don't forget that Meganium can search for Holon's Pokémon as Energy. If you lead with T1 Chikorita, attach Energy into T2 Rare Candy Meganium, you can grab a Holon's Pokémon as the second Energy and start attacking with Delta Reduction immediately.

Delta Reduction is going to be your main attack. It's cheap, does a decent amount of damage, and reduces your opponent's offense, especially if they're using spread damage attacks. Spam it while you look for opportunities to shave turns off attacking by getting Feraligatr into play (+10 damage), or attaching a 3rd Energy and using Mega Impact (+20 damage).

Feraligatr serves a two purposes. One, it boosts your damage output, and two, it can Drag Off opposing Pokémon to soften them up or make the opponent waste resources getting them out of the Active Spot. Notably, Pidgeot is weak to Feraligatr, and Dragging it Off once with Double Rainbow Energy attached, followed by attaching Holon's Castform, returning the DRE, and Dragging Off again KOs the Pidgeot.

Sceptile ex δ is your ace in the hole. It shuts off ex Powers (notably Electrode ex), and hits for huge numbers late-game, even if it needs 3 Energy to attack under its own Poké-Body. δ Rainbow Energy or Holon's Castform can pay for the Psychic in its attack cost.

Unique Points

This deck has a 1-1-1 Sceptile ex δ line. Teching Sceptile ex is not new, but including the Grovyle is. With Meganium δ, this is a wise choice, as you can search all the pieces to evolve into Sceptile ex off one Evolutionary Call even if you're missing Rare Candy.

This deck has the anti-control Mew ☆ δ + Warp Energy + Holon's Castform package. Mew hits Arcanine ex for Weakness, a Pokémon that would otherwise walk all over the rest of the deck.

Tweaks

Latios ex δ: Over Mew ☆ δ. Has 0 Retreat, so it can retreat for free to Holon's Castform early-game, and act as a pivot for Warp Energy later. It also beats Arcanine ex more handily than Mew.

Strengths

This deck aims for balance, not overly relying on one thing which can fall apart if your opponent throws up a counter and you're out of answers for it. Cursed Stone usually piles a lot of damage onto Stage 2 decks since both Pidgeot and the Stage 2 can get hit by it, but the only Power-haver in this deck is Meganium, and you have Mr. Briney's Compassion to scoop it up. Crystal Beach counters Double Rainbow Energy and Holon's Castform, but you have δ Rainbow Energy to pay for colored costs through it. You have four attacking types, and multiple ways of getting a Pokémon out of the Active (Briney, Warp Point, Warp Energy).

Weaknesses

Unlike Pidgeot, Meganium can't search up Trainers. You have to draw into those naturally with your Supporters. If you're completely out of Stage 1s because they got Prized or discarded, Meganium can't build you up to the Stage 2; you have to draw into Rare Candy to do that.

Meganium can get walled by Fighting Resistance. While the most common Fighting resist (Pidgeot) is punished by Feraligatr, there are some others which may be neutral to (Dark Dragonite) or even resist (Flygon δ) it.