User blog comment:IamJakuhoRaikoben/Chapter 468: Memory of the Stars, Review./@comment-24277053-20160109232549/@comment-7418318-20160109233736

How is it the children's fault? They didn't decide to go to the future... hell they didn't even KNOW they went through time.

The ones at fault are Zeref and Anna and to a lesser degree Layla herself, since she could have theoretically called the whole plan off until she got all 12 keys, even if it meant pushing the duty down another generation or more.

Regarind Zoldeo, even in the Tenrou arc he was said he was a loyal and upstanding servant and friend to Layla, but something happened on his journey that turn him down a dark path (fall to the dark side, fall into depravity, ect...), so this is completely in keeping with what we know about him.

Actually the guilt over this murder might be the very thing that started his fall. First in his grief he kills someone who's actually innocent of any crime (being out of touch can hardly be considered a crime, especially since Grammi wouldn't have known about Eclipse), then in his guilt over the crime he runns off and from there he spirals further and further into the darker regions of the Human psyche.

And as the final two nails in the coffin he get's himself stuck in a half-goat body that also affects his mind (why else would he have picked up Capricorns speech-idiosyncrasies?) and finally falls in with the manipulative puppetmaster Hades.

It's hardly a surprise he ended up more or less mad after all of that.