A Combiner robot needs comtributions from every bot that forms it, and Optimus Maximus is no different. Optimus Prime can bring the courage. Prowl can provide the strategy. Sunstreaker? He makes this Combiner look goooood.
Pre-mission psych-screening report by Rung, Autobot Psy-Ops Speciallist:
Sunstreaker has always enjoyed spending time on Earth, especially since humans tend to stare at him in both robot and vehicle mode. At his spark, Sunstreaker is a courageous and skilled soldier – it’s just that his spark is covered by the most stunning and shiny metal you’ve ever seen. The only Cybertroniam with nearly the same flash and style is his twin brother Sideswipe. Aside from him being yellow and Sideswipe being red, there’s one other easy way to tell them apart. According to Sunstreaker, “I’m the good-looking one.” Carries a highly polished cyber machete as well as a high-yield electron pulse cannon capable of firing 3000 bursts per second.
Conclusion: Cleared for mission
History(extracted from compulsory biographical download):
Sunstreaker has been an Autobot stalwart: a volunteer for the Ark that first landed on Earth as well as member of the initial crew aboard the Lost Light spacecraft. He’s an interesting study – conceited enough to crash a shuttle while string at his own reflection, but selfless enough to detonate a bridge alone while his teammates escapte. Forms either an arm or a leg of Optimus Maximus, the combined form of Optimus Prime