[Sombre]

In terms of national spells, to start with they are going to have at least one warp lightning spell which uses lightning but isn't air magic in any way shape or form, at least one plague/disease/poison spell which doesn't use water or nature and possibly a copy of the crossbreeding spell with slightly different path costs so it can be used by lucky moulder leaders (they will have some kind of rare NB random I think). The plague priests may well also get NB randoms of some kind - I might even allow the nation to blood sacrifice, should they somehow get enough bloodslaves to do so.

Basically though, the main skaven paths are EFDS. The Grey seers get minor EF with good DS. The warlocks get EF with possible but unlikely D. The pestilens leaders get D.

There will be summons in the construction school which are EF, ED, DF etc - the warlock schools. There will also be the high level construction summon The Screaming Bell, which will require Grey Seer magic. The Doomwheel, also in construction, will require a lucky warlock magic selection or the magic of the pretender, or empowerment/boosters of some kind to use.

I might put Moulder summons in death/nature/blood, I haven't given those spells much thought - mostly they are just called in by Moulder leaders using summon allies or auto spawning.