Agreed, you can keep him rather safe, but there is increased risk with the miscast, but increase reward from the new magic. Cast the augment to give a unit killing blow...the center of my battle line is a horde of skeleton spear-men with a tomb prince and a necrotect in the unit, cast the augment killing blow on that unit and you have up to 40 weapon skill 6, re-rollable, killing blow attacks coming your way. Group of tomb Guard on the other flank and they are still nasty all by themselves, through in a chariot unit now at str 5 (from rank bonus, and rank only needing 3 models) and d6 a pop, cheaper bone giant, couple scorpions, and a new monster....adds up to a nice little army.
sorry for rant, got excited.
I think the new book is solid, lots of synergy and thus a lot of room to play it well but a lot of room to mess it up.