Drift (ドリフト Dorifuto) was not always an Autobot. In fact, he slaughtered quite a few when he was known as the Decepticon Deadlock. But Deadlock's eyes were opened to what the Transformers' war had become when he stumbled across a lost faction of neutral Transformers long since forgotten. He discarded his ruthless ways, abandoned his guns for swords, and changed his name and appearance.
When Drift returned to the Transformer war to make right what he put wrong, he was a bot of few words and disciplined action. Because of his brutal past, Drift isn't well-liked or trusted by a few of the Autobots. The rest don't seem to care, so long as his skills are used against the other side!
In addition to the two swords kept in his hip scabbards, Drift carries a legendary Great Sword. An ancient weapon that predates modern civilization, the Great Sword draws upon the spark energy of its bearer, and as such must only be used in the most dire of circumstances.
In the previous incarnations of the character, Drift has always been able to transform into a helicopter. However, in Age of Extinction, he transforms into a 2013 Bugatti Veyron Grand Sport Vitesse.