He's the Author of Rook, who, quite ironically, was caught between fainting and squealing with joy when he first met them. He's also, quite ironically, the "LEADER" of the Real World Author Fighters.
Although he was indifferent, he got into the action sometime after Kay (Kitten Hachi-Chan's Author) was trapped within her own mind...but takes a bigger role when the Real World Author Fighters were sent to an alternate Super Robot Wars universe. As the mantle of leader and training under a reformed Master Asia, he starts to act more like his Author Fighter Counterpart...to the point where he would even die for a friend.
One of the few "Real World" bystanders, and Andrew's younger brother (which gives out the impression that Plague was modeled as a future version of him), David was one of the "saner" few after they accidentally made Diane, the Beautifly Pokemorph, kiss the Real World version of Ross.
Despite having been at Andrew's throat, he would rather stand by his side in order to get back home rather than walk out.
He's also TimeFire II after Rook swiped the TimeFire Changer and Wandrex erased its memory. Better to steal it than leave it with an insane madman who would kill off anyone Blue. In the Super Robot Wars-verse, he commands the V-Rex.
Another "Real World" bystander, Nick is Andrew's best friend. He was introduced as a rescued bystander thanks to the efforts of Travis Teran as the JAKQ Joker Ranger.
He's a parallel to Shikamaru, only without the troublesome catch phrase. If it was any consolation, he had to help out in order to get home, but mostly it was to help the team on tactics.
He's also Kamen Rider Caucasus in case he needed to defend himself.
This one was rarely seen, but a good representation of what he was first like and an homage to the first Blue Power Ranger (Billy Cranston) because he was geeky. Right now, Nick holds it because of that reason, but we haven't seen him use it.
David's personal transformation, as mentioned earlier. If anything, he was the only one, at the time, to actually have a Giant Robot to combat with. Despite using V-Rex, he's actually a green belt in Tang Soo Do, so he's the only Real World "Author Fighter" to know Martial Arts.
Kamen Rider Caucasus
Nick's personal transformation. Used in the battle against the Hot Rod Heartless, Nick hasn't been seen with it since he took up the mantle of Tactics Advisor.
When the Dinosaur Skull bonked Andrew on the head, it gave him the ability to change into Fire Dinosaur. However, the last time he was seen with it was in a fight against a demonic version of Green Shinobi, which was unknown if it simply disappeared or was taken by Joker.
Kamen Rider Den-O
After accidentally finding the spare Hyper Pass (and being possessed by all four Taros), Andrew gained the ability to become Den-O along with it. However, he's only one of two, as Ryotaro Nogami has the other one. He also explained to Tsukasa, or Decade, that the cards he used in Decade Episode 16 were to change forms. Also, he warns Yuusuke Onadera to not kick anyone in the neck, which was a reference to Decade Episode 15. Oddly enough, he also stabbed Panther Caroso, or Kamen Rider Alternative, in the butt.
While not a Tokusatsu Transformation, the Mask was revealed to be in his possession after having a mental breakdown. Oddly enough, he can communicate with it. The only transformation he used was to distract Kay from the Bleach group and reveal the Bobobo Group to them.
This is also the Jim Carrey incarnation since only he and Rook can use said form.
Given to Shruikenger in order to defend himself against a Putrid Attack in Konoha, Andrew knew what to do since he's seen this kind of thing before. What was ironic was that he made a reference to Richard Brown, who had helped the original Shinkengers out against a fire elephant monster.
Because of a Sparda Seed, Andrew had managed to actually gain the power of Sparda...and when Kai attacked his brain, the Devil Trigger manifested into its purest form. However, he experimented with it when he found Nevan's guitar/scythe in Venice, Italy.
Kamen Rider Odin
When he first found the deck, he thought he was going to be controlled. If anything, it was just an unused prototype Kenzaki discarded when he found out the Contract Monsters involved were female...except for Femme's, who was Male. Now he's the Prototype Odin.
Oddly enough, their first meeting was in the alternate Super Robot Wars universe. However, they're on the terms of "friendly rivals" after defeating the Glorft. Tsukasa pointed out that their "relationship was like Decade and DiEnd." Oddly enough, they confirmed it. Despite being allies, they're hard-boiled men that would probably kick each others' butts as soon as they would meet.
Ross of the Real World
Andrew sees Ross as a friend, although they were forced to fight each other once. He had blamed himself for the "death" of Ross, but after learning that Joker was an EM Being and Hades revealing that he needed a Getter Emperor to get Ross out of there, he makes it his mission to find him and apologize.
Kay (Kitten Hachi-Chan)
Not much can be said, but Andrew sees her as a sister...a crazy fangirl-ish sister that has an insanity streak, but a sister none the less. He tends to watch what he says because Rook had mentioned that she and Ryan (Lunatic121) should get a room. He's also more wary about Hare, Kay's patron summon.
(to Yuusuke) "Try not to kick him in the head."
"Before you kill me, I have to ask...what's your game? Why attack a Ninja Village?"
"TRIBE ON!" (with Fire Dinosaur)
"I don't care what anyone says. I'm going to kill them." (referring to the Joker and Joka.)
(Refers to some being with ultimate power) Ah, crap.