There is a very defining moment when Garth realizes–years after the other has left prison for good, joined the Legion and proven himself a valuable member–that he worries about his brother and that his brother still worries about him.
That moment happens to be during a particular mission on Rimbor. It wasn't anything tremendously special, just taking down a large cluster of Scavengers and delivering back the goods they stole from a superhero museum that someone had the stupid idea to place underground. Lack of light meaning lack of damage or some useless drivel.
They'd kicked Scavenger butt, retrieved the items, mostly Nth Metal tools from the Thanagarian Invasion of Earth and some structural schematics the Martian Manhunter had made hundreds of years before that were still being decoded and marveled over, and had been in the museum returning said items when Garth realized that they'd missed one of the larger Scavenger field leaders.
Of course, he only realized this when his head was smashed into a wall (lots of tiles, lots of sharp points sticking to his skin on impact) and the particular asshole had him near unconscious, ugly teeth showing with this awful smile that Garth had only seen on despots and sex offenders.
Turns out he was right on one count, with the man pawing at his suit before the head trauma fully kicked in and Garth passed out with slimy, disgusting, dirty fingers locating his zipper…
He wakes up to blood decorating the front of his suit, but he is uninjured and the clothing is not torn and then he's blinking across the medical bed at the chair with the figure that had been sleeping most uncomfortable, words spilling out of his mouth before he can help it, "Fucking hell, Mekt!"
The shout is very double-edged in reaction, getting Mekt awake and looking up at him like someone had fired a solar cannon and also making the impact marks in the back of Garth's skull and under the thick bandage of his forehead throb like a sucker punch.
The redhead paid no mind to his personal discomfort, though. Sitting up as Mekt started to try and stand up from his seat with some difficulty. One leg was in a cast that still smelled wet; both of his hands were wrapped in gauze Garth knew for a fact Luornu had to apply because the sedatives and powders for healing in the fabrics needed to be applied quickly and efficiently with three sets of hands as a single individual would pass out from the smell; his nose had been broken and reset with a bandage taped across the red crusting scab of it; and as Mekt was also out of his own suit, donning simple grey shirt and sweats (no socks, his feet probably freezing) Garth could see a multitude of fresh bruising along arms, neck and his face where his left eye was hard pressed to stay open with a cut along it.
Garth felt sick at the sight of a hand perfectly printed in bruising around Mekt's neck.
"Are you alright?"
Neither is really sure who said it first.