First of all, Blacephalons GX attack is a phenomenal T1 option and prevents being delayed by having to KO a non-GX later on in the game

Sort Card Type Hoppip #83Common $10.40 Hoppip #61Common $0.51 Hoppip #55Common $0.65 Hoppip #112Common $1.19 Hoppip #57Common $0.51 Hoppip #90Common $0.30 Hoppip #67Common $0.48 Hoppip #1Common $0.34 Hoppip #3Common $0.17 Hoppip #2Common $0.05 Hoppip #1Common $0.19 Hoppip #96Shiny Rare $4.27 Hoppip #1Common $0.12 Hoppip #1Common $0.20 Hoppip #4None $0.44 Hoppip #3Common $0.94 Hoppip - 005/190 #5None $0.11 Hoppip - 005/190 (Mirror Holofoil) #5None $0.81 Hoppip - 008/095 #8Common $0.88 Hoppip - 009/095 #9Common $0.62 Hoppip - 195/190 #195Shiny Rare $1.56 Hoppip (11) #11Common $0.20 Hoppip (12) #12Common $0.23 Hoppip (67) - 2010 (Yuka Furusawa) #67Common $1.86 Hoppip (90) - 2010 (Yuka Furusawa) #90Common $2.29 Hoppip (Mirror Holofoil) #4None $2.75 Hoppip #83Common $10.40 Hoppip #96Shiny Rare $4.27 Hoppip (Mirror Holofoil) #4None $2.75 Hoppip (90) - 2010 (Yuka Furusawa) #90Common $2.29 Hoppip (67) - 2010 (Yuka Furusawa) #67Common $1.86 Hoppip - 195/190 #195Shiny Rare $1.56 Hoppip #112Common $1.19 Hoppip #3Common $0.94 Hoppip - 008/095 #8Common $0.88 Hoppip - 005/190 (Mirror Holofoil) #5None $0.81

This is not one of the strongest points but is a supporting one
In general, I think such Gimmick decks can be built with the following parameters: 11-16 Lands 9-16 copies of Card A (Hero, Rat, Elves etc.) 4-8 copies of Card B (Dark Ritual, Crusade, Giant Growth) Remaining cards are miscellaneous inclusions or singletons
In a deck rife with discard-based spells, Codie can be used to potentially cause opponents to discard yet even more cards
It featuresPokmon-EX,Mega EvolutionandPokmon BREAK." -bulbapedia