I remember reading about a theory on a reddit thread about what happened during the fall of Gaiseric's empire with 4 or 5 angels appearing. The theory is that an Incarnation Ceremony took place there, with the 5th member of the then Godhand being incarnated like Griffith did during the Conviction Arc (This goes well with Skull Knight saying the incarnation ceremony happens every thousand years and the fall of Gaiseric's empire being a thousand years ago as well). The inconsistency of the number of angels is born from this according to the theory: the 4 angels are actually the 4 Kings of the Astral World summoned by a mage to protect the city from the outbreak of chaos caused by the Incarnation Ceremony. Then the alleged 5th Angel is the Godhand member that got incarnated. The theory goes on to speculate that maybe Gaiseric (eventually being Skull Knight) and the mage (possibly being Flora) defeats the incarnated Godhand member.I'm not sure how. The God Hand said they needed all five members together in order to kick things off.
This theory makes it such that there have been another set of Godhand before and that they got completed (having 5 members), incarnated the 5th member and a man owning (or will own) the berserker armor and a mage working together to bring down the incarnated Godhand member. So I really find it interesting to ponder about the possibility brought up here that an Age of Darkness (or atleast an attempt to bring one about) may have already happened in the past and that what's happening now might be part of a cycle repeating itself.
The hole, or rather weakness, in this theory is there never was a solid implication that there was a past Godhand before the current one. The timeline we know fits really well with the theory though, especially since the entire formation of the current Godhand happened well after the fall of Gaiseric's empire (if the 'every 216 years' thing is absolute and consistent) and that Skull Knight is said to be on the opposition of the Godhand's goals for a thousand years.
I apologize if this comes off as off-topic. I could post the link to the reddit thread if anyone wants to read the theory from the original source (if that's allowed). Credits to -SSubzero- from reddit who shared this theory (he/she might even be here idk).