Dark Naga CR8?

[JacktheRabbit]

A Dark Naga has several different abilities in addition to casting spells as a 7th level sorcerer.

What CR should this foe actually be?

 

[Merlion]

Well as I've said before...dont even get me started on the challenge rating system.
Its real hard to say about one creature WITHOUT a total revamp discussion of the system but just offhand me myself I'd say more like 10ish. thats for the dark naga alone of course...and brings him to the same listed CR as the Gaurdian Naga. But the Gaurdian should probably be more like 12ish so..