I'm not sure if it was ever explained, but why was it that God or the God Hand decided that Griffth would be the one to be incarnated during the 1000 year ceremony. He's the youngest of the five current God Hand members and I would assume that the other members have seniority over him. Slan expressed her desire of being made flesh when she appear at Qliphoth, so why is it that a more senior member of the God Hand would lose out to a new member.
Also, would it be possible/plausible if Skullknight was once a member of the God Hand himself? If we take into account that Gaiseric, and the tale Charlotte told Guts/Casca when they were rescuing Griffth, that Gaiseric's empire vanished in one night (my memory is a little hazy, but I think that's what she said, I'll have to double check), could it have been that Gaiseric used a Crimson Beherlit to become a member of the God Hand by sacrificing what perhaps meant most to him, his empire? He could've been incarnated in the last ceremony that took place 1000 years ago.
Also, would it be possible/plausible if Skullknight was once a member of the God Hand himself? If we take into account that Gaiseric, and the tale Charlotte told Guts/Casca when they were rescuing Griffth, that Gaiseric's empire vanished in one night (my memory is a little hazy, but I think that's what she said, I'll have to double check), could it have been that Gaiseric used a Crimson Beherlit to become a member of the God Hand by sacrificing what perhaps meant most to him, his empire? He could've been incarnated in the last ceremony that took place 1000 years ago.