This is underrated af. Really makes you think how Guda managed to stay sane after all the stuff they've been through, destroying entire civilizations 7 times over and all. Even when nothing's working out, they try their all to fix it because they refuse stand by and watch. They continue to fight and struggle despite being an Ordinary Person™. Without the supports from the servants and chaldea staff they probably would've broke countless times already.
Well... he wasn't. His "sanity" is the proof that he was never sane anymore. The fact that he managed to break free from Garden of Lostwill means his mental state is already beyond a normal human. It was revealed that he had an unhealthy obsession of finishing a mission, hence why despite the emotional turmoil he had been through, he still has to finish the mission assigned to him. And all this while refusing to let go of his humanity and chose to keep himself feel guilty for every inhuman actions he did. I mean, there's definitely a reason why an Avenger, an Abyssal Worm, and Yog-Sothoth's Key took a liking to him and living rent free inside his head
