That is actually a pretty good idea. A good few years after the angels arrive, the orcs arrive close behind and ready for war. This would provide another real element of plot, especially if one of the other roleplayers decide to use an orc as their character.

As for the rune based magic, magic in this universe is very heavily influenced by two things. The inherent magical ability of the race, and the personality of the person wishing to practice magic. For example, somebody who is hot headed and prone to overlooking details would be close in line with the element of fire, allowing them to much more easily control the element. 

It was an old idea I never used for anything and something I am still looking to tweak before really using it completely, the only problem is that finishing up this kind of magic would require me seeing how people try to develop their characters around a magic system where magic that directly conflicts with their character's personality can be just as dangerous for the user as it would be for the targets.