So I was looking over the death knight, and saw that there was a template that could be added to it. The CR is +3, and has to be added to a creature of at least 6 HD. This makes it CR 9. You then add this other template which allows it to summon skeletons equal to its HD. So, you could have nine skeleton warriors at 1 HD each, or you could have a skeleton chimera at 9 HD, etc. This increases the death knight's CR by 1/2. I'm serious about this. How does that work? Your creature is CR 9.5, but aren't they usually an even number?