He has trust issues that make him tough to work with and argumentative in many cases.
Cliffjumper came from a large, and very poor, family unit back on Cybertron. A boisterous family they were all close as anything.
Then the war started and every single one of Cliffjumpers family turned on him, pledging allegience to the Decepticon cause.
Horrified, Cliffjumper had tried to beg and plead with them all, pointing out that their so-called “glorious leader” Megatron was actually a rich snob who looked down on mechs of their ‘repute’, but none of them listened. In fact they made many attempts to lure him into traps, kill him or convert him.
In hindsight it really is no surprise he has trust issues after all that.
He can be very straightforward and blunt without realising how rude he comes across to others, in the close-knit, energetic environment he grew up in it was just normal to be so loud and direct.
He HATES getting lost.
He hates getting lost ALONE even more so. Despite his trust issues being lost and alone without someone he can fall back on really messes with him.
Instantly harangued Mirage the moment they met. Stupid rich bots. THIS WAR IS ALL YOUR FAULT! Probably in league with that entitled money-bags Megatron!! (It only got worse when he found out Mirage could turn invisible).
Gradually calmed down, however, when watching Mirage blunder through a conversation with other Autobots and it became blindingly obvious that Mirage was just socially clueless.
They have a close on-off friendship with Cliffjumper keeping Mirage grounded in reality and helping rid him of unfortunate lingering effects o his upbringing, while he enjoys potentially having someone he can trust again…. nnnnnot quite.
Cliffjumper is exceedingly aggresive to all ‘cons due to them taking his entire family in one swoop and would like nothing more than to erase them all off the planet, meanwhile Mirage is not fond of war and finds the Decepticons behaviour suspiciously violent making him a bit more reluctant to harm them.