Android 21 - 01

My third Dragon Ball OC, Android 21. He is exclusive to Dragon Ball GT, so it stands to reason that he's even more non-canon. I created him as though the creatours of the show made him for the sake of making him. As if they were to say, "we felt like putting this guy in here, here he is." He has no true purpose in the storyline beyond his introduction, other than being cool.

Name - 21
Species - Android
Starting Age - Not applicable. Appears 20
Debut - Dragon Ball GT, Episode 44
Armaments - Hidden Energy Cannon
Attacks - Pending...
Story - 1 - He officially appears four episodes priour to his stated debut, but it would merely of his dormant silhouette. Priour, Android 21 is the only remaining Android of Dr. Gero's to have survived the destruction of Dr. Gero's lab back in Dragon Ball Z. While Piccolo destroyed Cell's spy-bot, Android 21 still had his own. As a result, it followed Gokuh everywhere during the Saiya-jin Saga, and into space on Gokuh's space ship. When everybody on Namek was teleported to Earth, so was the spy-bot. Beyond that, it remained on Earth and witnessed the events of the Android, Cell, and Majin-Buu sagas. It travelled into space with Gokuh, Trunks, Pan, and my other OC Break, and witnessed those events. However, being that Dr. Gero was dead, Android 21 saw no point in awakening from his capsule, and merely watched through the spy-bot. When Dr. Gero and Dr. Myuu caused the break-out from Hell (HFIL) and created the two Android 17's however, Android 21, just as rebellious as 17 and 18, broke free of his capsule and aided in the battle against Super Android 17. Due to Android 17's ability to drain and store energy, 21's infinite energy generatour proved to be the perfect distraction for Gokuh to battle Super 17 and land the finishing blow. Beyond that, 21 aided greatly in the search for the Black Star Dragon Balls, and the battles against the Evil Shenrons. He found his first defeat at the hands of the final evil Shenron, Yi Xing Shenron (Syn Shenron, Omega Shenron) but doesn't die. He is embraced by Android 18 as something of a brother-figure. After Gokuh says his final farewell, 18 offers 21 a home with her and her husband Kuririn (Krillin)
2 - Android 21 is the first non-Saiya-jin (Saiyan) who can go Super-Saiya-jin (Super Saiyan). Because the spy-bot was watching Gokuh and company throughout the remainder of their adventures, the spy-bot was watching every Saiya-jin who transformed into a Super Saiya-jin. As a result, the remaining computers tending to Android 21's stasis were able to program in the first Super Saiya-jin transformation level. However the programming was filled with so many lines of code, that it had begun programming just after Gokuh teleported everybody from Namek to Earth (Dragon Ball Z Furiza Saga) and finished just as the two Android 17's met one another (Dragon Ball GT Super 17 Saga). The Ultra Super Saiya-jin (Super Form), Super Saiya-jin 2, Super Saiya-jin 3, and Super Saiya-jin 4 were all pending in the computers, but each program would take even longer than the first. In fact, it still would not have finished even Super Saiya-jin 2, 3 or 4 by the time Pan is featured in the final scene of Dragon Ball GT as an old woman. Android 21 uses this transformation as necessary, and does his best to teach it to Pan throughout the story. The two form an unlikely friendship because of it, despite the fact that he never manages to teach Pan to transform. He occasionally receives grief from Vegeta in the form of infurated complaints, due to the fact that Android 21 was created of an Earthling Human, and not a Saiya-jin.

This was one Original Character whose Mary-Sue-ishness can actually be explained away, and accepted, as one of GT's unofficial storylines.
The first point being his origins. It stands to reason that Dr. Gero's computers would've continued upgrading Androids 16, 17, and 18 if Android 20 had not awakened them in the Android Saga. As a result, the spy-bot would've eventually added the Super Saiya-jin data in, and the computers began to program those three to turn Super Saiya-jin. To make up for this, it also stands to reason that such a transformation would take hundereds of thousands of lines of code, perhaps millions, and would take a long time to program.
Secondly, you have to remember that Dragon Ball GT is, to a certain degree, non-canon (unofficial) due to Akira Toriyama's (the creatour of Dragon Ball) limited involvement. You see, the manga (comic) ended with the events of Dragon Ball Z, where Gokuh leaves to train Uubuu (Uub). Dragon Ball GT was anime-exclusive, and canon only to the continuity of the anime.