My friend and I have played several games of End of Times now and I was re-reading the rules for summoning units. I am sure that you can only summon something from the undead legions list... however I can't find it in the rules!
Is it legal for a wizard using the Lore of Undeath to summon a unit/character/monster (depending on the spell) from an army other than the Undead Legions (with a few exceptions Vampires/Tomb Kings)?
If not where does it state restrictions on what can be summoned?