To give you a warning: This theory is fully based on the idea that Argonaut is canon. I know it was never confirmed to be, but with everything we have seen, especially that SS of vol 17 of Tiona... I just can't imagine it not being canon. Even if it truly isn't canon, I'm still gonna share this and would like to hear your opinions.
Well, for a starter, I don't know if all of you watched the extra-story of Argonaut where Zeus reads the story to Bell. If you didn't, Zeus basically says that it was his favorite hero story and that he just couldn't wait to see what Argo would do next, before turning to Bell and saying some words that we can actually find in vol 11, when Bell is fighting Gors to protect Eina (if I remember well, of course), telling him that Bell's story was his alone and that he shouldn't let anyone decide for him. Then, when you take into account that Argonaut's spirit was a thunder spirit, called Jupiter, Zeus roman name (not saying it was Zeus himself, that isn't even possible), it pretty clear that Jupiter had a connection to Zeus. Then, when Argo made his speech on how the Age of the heroes was starting, Orna, I think, said she thought she heard heaven laughing and saying: Try all you want!! At the end of the game, Hermes says that he understood why Zeus looked so enthusiastically when looking at the lower world. I think it is pretty clear that the one that laughed was Zeus.
What am I trying to say with this? Simple: Zeus knows Bell is Argonaut.
What does this have anything to do with Zeus believing Bell ain't fit to be an adventurer? Well... I wouldn't say it is exactly the answer for it, but something in the middle.
Zeus raised Bell ever since he was a newborn. He was Bell's only parental figure and knows virtually everything about him. Now think: the guy had a familia for 1000 years and he saw how adventurers were. And let's be real... adventurers, in general, aren't exactly the best people. Ais herself already said that they all have distortions. Zeus himself more than likely noticed this. And then he raises the guy that started it all and realizes that Bell is kind, naive, good-natured (something he probably already knew) and when the world strikes him he gets taken at back (just like what Ais said). At that point, knowing how adventurers are, and even though Bell had been the one to start the whole adventurers business, Zeus realized that Bell didn't have what it took to be an adventurer, he didn't have distortions or ambition, he was too kind, naive, etc. In the beginning, he probably thought Bell would do something great, but as time went on, he realized Bell was truly just a boy from the mountains, and not fitted for near-death experiences. I mean, Argo's story and Bell's story are pretty different at the beginning. True, they both lost their home, but Argo was a prince that saw everything happening and tried to save anyone. Bell, on the other hand, thinks he has always lived in the mountains with an all-caring grandfather.
When he understood this, and when receiving the info that something urgent had come up, he decided that he shouldn't be counting on Bell to solve the problem the world was in and decided that he would be the one to deal with it and create a world where his grandson could remain kind, good-natured and naive.
When you take all of this into account, it is not that surprising that when he heard that Bell leveled up, (probably heard from Hermes) he spitted the tea he was drinking out of shock, and then asked Hermes to take care of him. After all, he had been wrong and Bell was still the hero that he had been millenniums ago.
Well, that's it. Gigantic theory, I know.
