Gao Mikado/Deck

Gao usually uses the "Gao Formation" - a formation in which a player has 2 monsters and an item equipped without a monster in the center thus leaving him open to direct attacks. He incorporates many defensive cards (some of them having Move) to compensate for this.

Season 1
Gao mainly uses Dragon World decks featuring Drum Bunker Dragon as his Buddy. Due to his lack of experience in deck building, 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.

"Ha! Unleash Baku's super explosive dragon deck! Dragon Blast Fury, Luminize!"

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.

"Showering the sky with scorching sun rockets! Soleil Dragon Deck, Luminize!"

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.

"Unleash fighting spirit, bravery and courage! Luminize! The mighty Magic Guts!"

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.

"Cracking the skies and rumbling the ground! Luminize! The forceful Tempest Thunder Knights!"

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.

"If you take a chance and reach for the sky, the clouds will unmask the sun! Now Luminize! Brave Soleil!"

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.

"The most powerful deck ever, blazing a path to the future! Luminize! Explosive Dragon Fang!"

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. After Drum obtains a new form, Gao rebuilds his deck. Drum's new skill allows him to stand after destroying a monster, and Gao's new transforming card, Fiery Inspector, Prominence Burst, gains a critical after a monster is destroyed. For his fight against Kazane, he added Count Dawn to his deck so he could see Kazane again.

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

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

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

His deck is later reconstructed after Drum becomes the Fifth Omni Dragon Lord, Drum. This deck is focused on abilities after damage is inflicted to the fighter. And the impact, Dragon Lord Initiation, Giga Howling Crusher!!, created after visiting Tenbu's spirit, allows Gao to deal damage equal to the critical of monsters and items on the field. His deck further improves when Drum became Fifth Omni Super Dragon Lord, Kaizer Drum, with his skill to allow the fighter to gain 1 life when the life is 0, as well as destroy a monster on the field.

"Howl, the roar of the Dragon Lord! Shine as bright as the sun! Luminize! Super Dragon Fifth Omni Formation!"

For his last battle against Yamigedo, he uses a new deck focused on all nine Omni Lords. This deck also focuses on the new impact, Unparalleled Arts, Omni Lord ∞ Burst!

"Roar, Breath of the Dragon King! Brighten the land like the sun! Luminize! Superdragon Fifth Omni Formation!"

Season 3
He uses a new deck, focused on cards with the Sun Dragon attribute, his new buddy Sun Dragon, Bal Dragon, the skills of Sun Fist, Balknuckle and his new impact monster, Bal Dragon, "Bal Burst Smasher!!". Bal uses this deck in episode 2.

"Rise, sun! Burn, Sun! Luminize! Scorching Sun Dragon!"

For the WBC Cup, his deck is tuned.

"Rise, sun! Burn, Sun! Luminize! Scorching Sun Dragon!"

After getting Bal back, Gao's deck improves, focusing on the abilities of Bal Dragon, "Bal Saucer Over Rush!". He then acquired the Dragon Force (Dragon World), which allowed him to attack over and over while linked with another Sun Dragon.

"Rise, sun! Burn, Sun! Luminize! Scorching Sun Dragon!"

His deck goes through some improvements, focusing on gaining abilities through link attacks, preventing damage with Sun Stone, Bal Flame, and using the Dragon Force to his full potential. During his fight with J Genesis, he obtains Super Sun Dragon, Balle Soleil.

"Colliding fists! Connecting hearts! Shine brightly! Super Sun! Luminize! Bullets of the Sun!"

For the final battle against Kyoya, his deck improves focusing on using the spell, Sun Deity's Choice, in order to use the powerful impact, Balle Soleil, "Eternal Bal-Blaster!", using the spell's ability to lead him to victory. He also uses all the Impacts and forms he required during his final fights with Bal Dragon.

Season 4
When Gao released Batzz, he also released a bunch of other Thunder Empire cards, and Baku made a deck from it.

"Rise up! Almighty dragon! Luminize! Demon Lord of Dragon Tempest!"

Official Version
Official decklists are posted here and 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)".