NONONONO THATS OK!! I get super duper happy when people like my ideas/writing, you don't get ittttt. Little excited creature (me) bounces around in joy like a pogo stick.
BUT YESSS. Bettel reuniting with Shinri few weeks in, at first clueless what the hell he is doing. Shinri shows Bettel Hakka's state and says he's keeping him alive just in case there's a cure. Bettel finds it weird but rubs it off. He couldn't bring himself to kill Hakka either. But slowly unravelling what Shinri is doing to keep Hakka kicking. Max luck strikes again that he could find half of tempus (i picture altare-axel-flayon have their own group) but one is undead and the other is mentally declining.

Luring people in is easy for shinri, minus morally but telling himself this is for Hakka is enough to keep him from giving up. Pretend to be an innocent survivor and offer to be together. Share supplies and take them out as they sleep. Bettel sometimes gets roped in, mostly for Shinri to look more innocent and all Bettel do is nod along, knowing the new person isn't going to last more than a week. It gets to a point Bettel doesn't bother to ask peoples names for his own sanity. He can't stand hearing about their personal lives, family and what not, knowing they will all meet the same fate.
This doesn't stop Shinri from comforting Bettel & reassuracing him (and partly himself) it's all ok. They are doing this for survival, for hakka, for tempus. But Bettel can tell behind all the polite half lies that Shinri is losing it. The only thing he is clinging onto is tempus & a theoretical ending of the zombies with a cure. Slowly for Bettel, Shinri is more terrifying than the zombies but he can't bring himself to leave hakka & shinri to their lonesome.