I first wanted to say that I built my Necromancer for two purposes Control and Creation of Undead.
When my character hit lv. 11 I was very excited to try out my new spell Create Undead. So I went to a tavern, memorized the spell and picked up spell components and headed to water works.
The spell costs 35 spell points and has a cool down of 600 seconds (10 minutes) and the spell component Black Onyx (The spell is a little different than the phb Create Undead :: d20srd.org )
(also keep in mind that a level 9 summon monster will have a cool down of 9 minuets)
So I enter the dungeon and make my way north to the first two kobolds and cast the spell creating a mummy.
The mummy was a cr 5 ((I am guessing ported straight out of the MM))
The Mummy defeated the Kobolds, and then 48 seconds into the spell broke free and attacked me. . .
This is where I am annoyed with the spell!
First they get a save to break my control every 3d12 + 12 seconds (thats a max of 36 seconds of the initial control and 12 seconds after)
My characters 6th Level Spell DC is 29. What that means (If Turbine buffed up the mummys saves then that would suck) is that the CR 5 mummy should have a will save of 8.
That means the mummy would have to roll a 20 to break the save. . .
(I tested this a couple times having to wait 10 min per cast and the outcome was about the same each time. I also tested it on gouls and ghasts which had about the same durations)
So I am spending 35 spell points and 2,658 gold pieces (roughly 265 gold pieces per cast) to cast this spell.
Now comes the math. . .
(for these numbers I used a max roll of 3 on the initial timer)
Shortest Duration would be 36 + 12 (the mummy's roll saved on the first chance would be 48 seconds).
Medium duration would be 36 seconds + 120 seconds (rolled a 20 on the mummy's tenth save)) for a total of 156 seconds (or 2 minuets 36 seconds)
A roll of 20 on his 20th save would put the spell duration at 36 + 240 = 276 (4 minuets 36 seconds)
What this shows is the spell cool down and the cost for the components and sp are unbalanced and imo totally a waste of time. Even if you are lucky and the mummy does not save for four min. that still leaves the 6 min left for the cool down. This spell needs major work and a look at what can be done to make it worth using.