@Übereil i would also choose conjuration for the undead spells

and the divine one means that if you gain 10 levels in block you would gain +10 to agility when you level up(if you choose to boost agility cause you can only boost 3 stats on each level-up) but the maximum is +5 so that would not be so effective.
but say you get +5 block and +5 blade you get +5 to agility and +5 to strength when you level up.

i hope it's a little clearer now. did you play morrowind? its the same system?