To start off, Aichi's first Ride of King of Knights, Alfred. The guy's completely and utterly being stomped by the Megacolony Units his opponent's using. And then he proceeds to draw Alfred and Ride it, accompanied by the Ride shout which is probably his second most famous behind 'stand up, my avatar'.
Aichi: Enter the fray! I ride the King of all Knights!
The above chant even gets an extra piece of awesome added to it when he Rides Alfred in one of his later fights:
Aichi: Grant me the strength to lead! Enter the fray!
Kai may be an absolute Base Breaker, but sure as hell he made one great impression in the second episode by riding Dragonic Overlord, widely regarded as his trump even with Vortex Dragon apparently usurping it, accompanied by one hell of an awesome line.
Kai: This is the real me! (Note however that he's lying and trying to convince Aichi that he is not a nice guy. And failing quite miserably.)
Misaki. Hell, Misaki. She trumps the main character in her first game. Yes, you heard me right. The compulsory female mainbeat the main character.
Beating Aichi isn't an impressive feat. Aichi loses a lot of battles, considering he's the main character.
Well, this was before it was established that was going to be happening a lot.
From Episode 22, Aichi's first Ride of Soul Savior Dragon. He's literally on the edge of defeat after Gouki used Demonic Sea King Buskirk's Soul Blast to set-up one of the most powerful fields he could. If Gouki gets another turn, Aichi loses. He proceeds to draw Soul Savior Dragon, which Kamui stated earlier (seen via flashback) he shouldn't use due to the difficulty. Aichi Rides Soul Savior Dragon and uses its Soul Blast, powering up his Rear Guards for a winning flurry of attacks. Not to mention the animation got kicked up about eleven gears to make the thing look damn freaking awesome.
It may represent Aichi getting Drunk on the Dark Side, but seriously, this line was awesome:
Episode 48. Aichi. Final Turn. Both terrifying and epic. It also comes complete with what can only be described as one of Vanguard's most epic BGMs so far. And...
Episode 50. The whole of it. But in particular Kai's Final Turn. Not only did he use Alfred Early, something we never expected to see in the anime but the entire thing was set to Believe in my Existence by JAM Project. And it ended with Aichi finally casting aside PSY Qualia and the Shadow Paladins to use his Royal Paladins once more
Blaster Dark: You'll regret it. Aichi: No. I won't. I'm sure of it.
Aichi standing up to Ren in episode 53.
Aichi: I don't want to become like you. ... I'm going to stick with a Vanguard fight that's different from yours. Then I'm going to fight you and win.
Aichi beating Koutei in Episode 56. His field is depleted, his hand is empty, and he will almost certainly lose on Koutei's next turn. But due to The Power of Friendship, he goes from near-certain defeat to victory. Complete with an awesome finishing shot of Blaster Blade unleashing an energy burst from his sword which knocks Enigman Storm flying. For reference, Blaster Blade is human-sized, while Enigman Storm is the size of a freaking Humongous Mecha.
What's even better is that Aichi does this without using PSY Qualia. He earns it through sheer determination and his bond with his Units. Indeed, this is referred to as his 'true power', even more valuable than PSY Qualia. This is why the Unit he draws is so significant, it represents the past and what Aichi always had. Even before getting PSY Qualia, he had his bond with his Units, and especially Blaster Blade, his avatar.
Aichi: Behold the king in his younger days, as he blazes a trail with his knights! I Ride Alfred Early! Aichi: Stand up again, my avatar! Superior Call, Blaster Blade!
Episode 57. Kai finally works up the courage to try and get Ren back from PSY Qualia. Ren taunts him about how powerful he has become and how now any task he can set his mind to is easy, he could even Take Over the World. They spend several turns exchanging blows, before Kai draws a certain card. What happens next is epic.
Ren gets a villainous one in the following episode. He lasts through Kai's attacks, even though Kai pulls off Dragonic Overlord The End's Persona Blast, and starts his own turn, stating that Kai will lose that turn. He then states that Kai isn't the only one with a trump card.
Ren: Crying out in despair in the chaos called silence... the power of shadowy darkness, obscuring all vision, is mine! I Cross Ride... Phantom Blaster Overlord!
Misaki avenging herself against Asaka using her eidetic memory, which she used to hate, to memorize every card she's going to draw, and in what order. A perfect blend of her unique strength and her deck.
Not only that, but the way she does it is particularly awesome. Asaka guards her 'one attack' with a guard which needs two Triggers to break. Completely unfazed, Misaki calls out the cards she'll Drive Check and gives the boosts to her Vanguard in advance. She's perfectly correct, and checks two Critical Triggers, breaking Asaka's guard and winning the game.
In Episode 63, Aichi attacks Ren's Vanguard (Blaster Dark) with his own (Blaster Blade). The two clash in avatar form and get into a sword-lock, as Aichi explains how Ren trampled on Kai's attempt to get through to him, saying that Ren is so hooked on PSY Qualia's power that he thinks it's okay to do whatever he wants. Finally, he declares he doesn't want to be like that and tells Ren straight to his face that getting addicted to PSY Qualia is a mistake before breaking the sword-lock and making an awesome slash with the Blaster Blade into the stunned Ren. Talk about taking a level in badass...
Episode 64 gave us a very understated one. Aichi declares he's had enough of Ren's mind games, and holds up a card. When we cut back to the action from the PSY Trio, he proceeds to reveal what it is, after making an awesome speech. And all while a very melancholic and sad, but very good BGM plays.
Aichi: Light isn't the only thing standing beside him. Darkness also stands with the King of Knights. Stand, my avatar! I Call... Blaster Dark!
Episode 65, being the season finale, was sure to have several. It didn't disappoint.
Having barely escaped defeat by sheer luck, Aichi looks like he's on the ropes and facing near-certain defeat. He begins to question which of his selves will fight, his power-hungry other self, or his self which despises PSY Qualia. The two selves have a strange experience in Aichi's mind, at which point they become one. Aichi makes his draw, and proceeds to unleash his greatest strength.
Aichi: Light and shadow become one... and then true power is born! I Ride... Majesty... LordBlaster!
One of the best is Aichi's final attack with Majesty Lord Blaster. Ren angrily declares he won't accept anyone, following Aichi's statement that he accepts Ren, and guards Majesty Lord Blaster's attack. Aichi makes his first drive check, and then smiles, reaching for the second card. He simply says 'Picture it', and as he speaks, the first chords of Believe in my Existence start to play. Aichi makes a speech on the value of Nakama, and reveals his second check, a Critical Trigger. After a long Crowning Moment of Heartwarming, Majesty makes the attack, impaling Phantom Blaster Overlord with his blade for a Critical 3 blow which Ren cannot possibly survive (by this point he doesn't have enough Heal Triggers left). With that final blow, Aichi wins.
