In the Yu-Gi-Oh! 5D's anime, Clear Mind (クリア・マインド Kuria Maindo) is the ability to control Ener-D with one's own heart. Achieving a state of Clear Mind is required in order to perform an Accel Synchro Summon. In the dub, it is also known as Perfect Synchronicity. When performed in the Japanese dub, Yusei shouts "Clear Mind!" before beginning the summoning chant for Shooting Star Dragon. In the English dub, he says his usual "Rev it up!".
One of the three requirements for Clear Mind is speed, shown by the fact that all instances of it have occurred only in Turbo Duels. In one instance, Primo was able to block this requirement by ordering his Diablo minions to surround his opponent, preventing acceleration.
The second requirement for Clear Mind is that the user's mind must be clear, psychologically speaking. The user must free themselves from all negativity in their mind and heart, and must maintain focus on the battle at hand and nothing else. Bruno is shown to excel at this, being able to ride straight through a wall of fire without even flinching while in this state. Yusei failed this requirement the first time he attempted an Accel Synchro Summon, due to Primo's taunting distracting him.
In many instances, Yusei has been able to achieve Clear Mind even when his mind wasn't totally clear, using the power of the Crimson Dragon to aid him. He has been able to successfully achieve Clear Mind without relying on the Crimson Dragon during one instance when he Dueled against Taro Yamashita.
Top Clear Mind
Top Clear Mind (トップ・クリア・マインド Toppu Kuria Maindo) is an enhanced state of Clear Mind, first introduced and performed by Antinomy during his second Duel against Yusei in episode 144. This state is necessary to perform a Delta Accel Synchro Summon. Its power greatly exceeds that of Clear Mind, as shown when Antinomy's Delta Accel Synchro Summon created a shock wave that caused the star nearby the Duel to collapse and turn into a black hole. According to Antinomy, to achieve such a state, the user must strongly believe in their own potential to exceed their limits.
While Yusei has never performed Top Clear Mind on screen, according to Z-one's printout, he must have learned to perform it at some time in the alternate future as he was shown possessing a Delta Accel Synchro monster. Z-one's arrival in the present time rewrote that future, causing Yusei to instead develop Over Top Clear Mind (see below).
Over Top Clear Mind
Over Top Clear Mind (オーバー・トップ・クリア・マインド Ōbā Toppu Kuria Maindo) is the highest known evolution of Clear Mind, greatly exceeding even the power of Top Clear Mind. It is first introduced by Yusei during his duel against Z-one in Episode 150, and is required in order to perform a Limit Over Accel Synchro Summon. When performed, it turned Yusei and his Duel Runner golden in color, possibly implying its god-like powers. To achieve this state, Yusei needed to possess the complete Mark of the Dragon, and, like Top Clear Mind, needed to strongly believe in the potential to exceed his limits, while also believing with the bonds of those closest to him such as friends or supporters.
- Yu-Gi-Oh! 5D's episode 107: "Primo's Plan, Part 2"
- Yu-Gi-Oh! 5D's episode 108: "Primo's Plan, Part 3"
- Yu-Gi-Oh! 5D's episode 122: "The Power to Believe! The Strongest Giant Zushin VS Shooting Star Dragon"