Cliche! The great mentor and father figure turns out to be evil due to his heart being corrupted, and the MC will have to surpass his father figure in order to purify him and bring him back to goodness again.
Also, isn't Ziggy supposed to be Hades' analogue here?
I think there are some translation errors. On page 18, Ziggy says the same line Hermit does.
Also on page 6 when Shiki said he was wondering about the erased momories, Weisz answers "Like a toilet" That doesn't make sense, context wise.
Either this was caused somewhat by Eden's One, or perhaps this might relate to what he saw during his journey and why he had to erase the memories of the others.
I think that if their memories were erased was either because the secret is on universal scale (like they could go to Fairy Tail's world xD) or either it'd be too easy if someone could hack them to do all the job for them