ooc ; some tidbits that I am keeping from my previous blog that are still canon to my Rodimus.
He has a chronic rust infection from when he was just a youngling living in Nyon. It flares up from time to time and usually puts him out of commission until the medigrade he takes resolves the infection. He has rust scarring on his face that he's buffed out and covered with silver, but it's still visible if you look closely.
He is, in fact, an outlier because of his flame capabilities. When he was a youngling, it was very difficult for him to control his combustion, especially if he was upset or overly excited. He still can combust from high emotions, but he has a much better handle on it now.
He has scarring on his spark-chamber from the blast he took from Megatron's cannon that the Matrix could not fix. Additionally, he has self-inflicted scars in the form of carvings of names of mechs who were once important to him, who hurt him, that he keeps as reminders not to let another Dealer happen.
While not directly related to First Aid, they were both adopted by the same mechs as younglings and are definitely brothers. First Aid is the older, but shorter sibling. Rodimus teases him about this because he used to be the shorter sibling until his Matrix upgrade.
Rodimus was part of the Wreckers for some time, up until the incident with Megatron - after the Matrix revived him, Rodimus never went back to the Wreckers.
Speaking of the incident, he has never fully forgiven Megatron for killing him. He meets him with hostility, but given time, he will let it go. Not forgive, but try to forget.
Rodimus is a lot smarter than he lets on - he prefers to be underestimated. He's nowhere near the level of some other mechs, but he has taught himself mechanics, explosives engineering, and much more, but he prefers to keep most of those things to himself; mechs are less likely to ask him to do things if they don't know what he can do.
Rodimus has chronic nightmares about the destruction of Nyon, the mechs he's lost, and especially, those who were lost through out the Lost Light's journey. Nyon has been and will always be his biggest regret and worst nightmare.