Nexus Prime TFP

Nexus Prime, known as the Wizard of Forms, is one of the Thirteen and is the first and greatest combiner. Unpredictable, he was fascinated by change and was a light-headed prankster. He is also a wielder of the Omni Saber and Cyber Caliber.

Transformers: The Covenant of Primus
Nexus was among the Thirteen created by Primus to defeat Unicron and witnessed the activation of the Well of Allsparks. He was good friends with Solus Prime-something that apparently sparked jealousy in some of their brethren-and was thought of as a joker, though Alpha Trion never once laughed at his jokes.

Transformers: Exiles
Nexus returned during the Great War, where he was formed from two Velocitronians - Clocker and Mainspring, one Cybertronian named Chaindrive, and two Junkions - Cannonspring and Pinion; each one holding a fragment of the Cyber Caliber.

He was eventually reformed when all his components came together. He immediately began to aid Optimus Prime and the Autobots in fighting off the Deceptions and saving Junkion. During the battle he noticed Megatron and mistook him for The Fallen. Overcome by memories of the loss and pain Megatronus had inflicted on the Thirteen, he charged directly at the Deception leader only to be surprised when he arrived that he was not his traitorous brother. He then proceeded to study Megatron intently, unnerving the Decepticon leader. Taking note of the Decepticon's name, jet mode, Dark Energon use and cannon adoring his right arm, Nexus was stunned at the clockwork precision by which history repeated itself. Before returning to the battle he warned Megatron that reminding a Prime of the Fallen was a very easy way to earn their wrath.

After the battle had ended and the Autobots and Decepticons prepared to leave, Nexus willingly split himself into five brand new Cybertronians to prevent the amoral Star Seekers from discovering his awesome power.

Trivia

 * Nexus Prime was originally called Nexus Maximus, when the character was first introduced; however, it was later discovered that this was a trademarked name belonging to an adult product, and thus Maximus was replaced with Prime.