Gao Mikado/Deck

Season 1
Gao mainly uses Dragon World decks featuring Drum Bunker Dragon as his Buddy. Due to his lack of experience in deck buliding, his decks are built by Baku Omori. As the series progresses, Gao's decks change to reflect Drum's changes and evolutions, using different Worlds occasionally.

Gao's first deck was themed around the Armordragon attribute. He mostly focuses on quickly dealing damage, mainly by attacking as many times as possible per turn, often leaving his center area open to attack with items. After obtaining Gargantua Punisher!!, Gao gives more focus on finishing the game with Punisher!!, so he added Steel Fist, Dragoknuckle to help increase his gauge quickly. This deck sets Gao's standard strategies

Baku and Kuguru later designed a new deck for Gao to use in the ABC cup so as to cover Gao's weakness of leaving his center area open too often by including monsters with the Move ability and adding more spells that increase attack and defense like more Dragoenergy and Wrath of Dragon.

The night before going to Sengoku, Baku and Kuguru build a magic world deck for Gao focused on drum's new form and his ability by adding cards that would help decrease his life and spells that would help him pay the gauge cost.

In episode 31, Gao's Dragon World deck once again changes, this time to the Thunder Knights archetype, with Drum's evolved form, Thunder Knights, Drum Bunker Dragon. This deck focus on the monster's Move ability, creating a balance of offense and defense. By using the set spell, Thunder Formation!, he is able to increase his gauge when a Thunder Knights moves to any position. It also acts as an impact card, letting Gao check any 3 cards on the top of his deck after he and all of his current monsters on the field are done attacking,allowing him to call another monster with Thunder Knights on its name to attack the opponent again.

After knowing the existence of Darkness Dragon World and Disaster,his Thunder Knights deck was further improved by Baku to prepare for any tough challenges to come in the future. When Gao was given the power by the mysterious force in his dream to defeat Disaster and Azi Dahaka,his Gargantua Punisher!! card evolves to Roaring Slash!! Gargantua Punisher!!.As it adds one more damage from his previous impact card,it makes Davide's attempt to win by cheating useless.

In episode 33, Gao uses a Dungeon World deck focused on the Adventurer attribute, with Brave, Drum as his buddy, which shows Drum's training results while in Dungeon World. This deck uses many mini games,like 'Rock,Paper,Scissors', relying on luck to activate certain monster effects and making Link Attacks to activate his Adventurers' abilities. His main item is Brave Equipment, Glory Seeker, allowing him to revive with 3 life points with its effect should his life reach 0.

Gao's second objective with this deck is to make the fight more fun and enjoyable for him and his opponent with the various mini games it offers as well as card versions of many of his friends who comically often excite/confuse their real counterparts and quickly embarrass them later.

After realizing Disaster's true intention in episode 45, he obtains a new deck. This deck returns to Gao's original Armordragon focus and Drum's base form as his Buddy again, but its improved with new ways to use his "Gao Formation" style as well as support for Drum's varied forms while also supporting his new Roaring Slash!! Gargantua Punisher!!. Gao now uses several Size 0 monsters which after attacking return to his hand and deck allowing him to attack 4 times per turn and still use his item, while Dragon Return System increases his Gauge every time they attack.

During a buddyfight against their fathers, Drum evolves Super Armordragon, Drum Breaker Dragon, and during Gao's fight against Kyoya, he evolves into Ultimate Neo Dragon, Drum the Future. Gao temporarily used Jackknife Dragon to help him return Tasuku to his side, so he included a few support cards from Jack.

Season 2
Baku built Gao a new deck which included Drum's new form, Crimson Battler, Drum Bunker Dragon and his brand new impact, Gigantic Crusher!!, which is different from his old impact Gargantua Punisher!!. The purpose was using the old Gao Formation, and to give Drum Penetrate when Gao equipped his new item, Crimson Fist, Dragoblaze, making him deal powerful attacks and using Gigantic Crusher!! to end the battle. He later added Fifth Omni Dragon Lord, Tenbu to his deck upon his request, and used it to win his battle against Death Shido.

"Burning like an inferno, with limitless spirit! Luminize! Crimson Dragon Fist!"

While fighting Death Sofia, he uses a Hero World deck with Buddy Police, Decker Drum as his buddy. His ability allows him to pay 2 gauge to destroy a monster. And Gao his an impact, Rampage Blaster! used to deal 3 damage only if he transforms himself into Explosive Takedown, Rampage Sonic. He used this deck again in his fight against First Omni Beast Lord, Ziun. After discovering that Tenbu is useful for all flags, he added it to his deck. Mach Braver's effect allows Gao to call him to the center so he can block an attack.

"Emergency Launch, from the eye of a storm! Luminize! Beaming Sunshine Guardians!"

When he was buddyfighting in H Episode 7: Meow, Meow! Cait Sith in Boots!, he was using Cait Sith in Boots as his buddy, resulting in Gao using Legend World temporarilly.

"To become stronger than I was yesterday, I will overcome any obstacles! Luminize! The Legend of Fairy Blade!" - Cat Sith

Official Version
Official decklists are posted here.

Trivia
In the Japanese version of the anime, Gao's first deck was called "Bakudora" (爆ドラ), an obvious pun on the fact Baku build his deck. This pun was lost in the English version of the anime, where the deck's name is directly translated to "Dragon Blast Fury", as Baku (爆) in Japanese means "Explosion", while Dora (ドラ) means "Dragon" in terms of transcription "doragon (ドラゴン)".