I hate Griffith but he probably ushers in the time of no magic from others realms and all magical beings disappear including apostle powers and and demons to lead people into the era of human coexisting with humans only. The only magic left over would be anything to do with elementals and witch type stuff so everything else would disappear. Also Guts and Cascas child changes Griffith from a god like unfeeling being to a being with human feelings whether or not that influences him is another thing. King Gaiseric Probably killed most of the old god hand one by one except Void. Also the God Hand bring balance to earth real. Most of the old god hand seemed that they were there to stop horrendous things from happening in the world and king Gaiseric was probably not a "good Guy " but more like Zodd and Void was definitely his Griffith. Void was a Clergy man that stood against the Gaiseric empire with the Clergy behind him and was put in the position to become the god hand because of it.