Only those who trained directly with Ket have that mark - meaning that the only living members with it are Marcus and Tsitua. But there are other ways to get back to the ship. I only used one of them to show the significance of who he is. 

I put something up. Orion isn't in that one because I'm bringing him in. We're gonna take this thread to another level I think. Sorry for going so long without a post. Life happens as you well know lol.