HEAVY SPOILERS
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In chapter 181, it's said that the cursed shackles also sealed his age and his flesh body, allowing him to neither die or age. And it worked since he couldn't kill himself. Then, he requested two shackles when he was banished the second time. During the time he was banished he wasn't a god, so HC can't keep him alive by being his most devoted believer. He was a human without luck and spiritual powers, but still didn't age nor die, and the reason was the cursed shackles.
I'm in book 5, so if there's something I don't know yet, please only say "you'll understand later"
Ok, I'm 1000% sure that when Ruoye grabed HC as the reliable something, HC was totally able to stay put in the ground, but decided he wanted to follow XL, you can't change my mind