When you've lived for a long time, you yell at clouds sometimes. [Most of the yelling was probably done during his first century. Teenagers.]
[Hopefully Hiryuu shaved their whiskers or something before he reincarnated?] It's pointless to think in those terms. Forget about those asshole gods for a moment. Many normal humans get extremely bad lives without them intervening in either good or bad ways; it's not like it's only about us. But humans still move forward and do what they can in their situations. We're as human as we are monster, so the more reason to just live.