
Dosgamer |

If he's an NPC with PC class levels his CR is 1 less than his level. For instance, a level 11 wizard would be CR 10 unless it has PC wealth and then it is CR 11. I'm sure you know, but CR 10 is not appropriate to put against a pair of low-level adventurers (APL is either 0 or 1 depending on how you feel about it).
If he's a hodgepodge of spell-like abilities and weird stats, then you would have to post his build and someone could help you figure out what an appropriate CR would be. Thanks!

Bobson |

i know its not appropriate but hes not gonna attack the players hes just gonna be there
Then he doesn't need a CR or a full stat block. CR is irrelevant if he's not going to be attacked.
What you should do is pick two appropriate kill spells (or just spells that would be kill spells to low level characters) such as phantasmal killer, enervation, or just regular ol' fireball, and one disable-but-not-kill spell (pantasmal web). If the PCs attack him, he casts either the disable or the kill as appropriate. If they continue attacking even when it's clear they're overmatched, he casts both kills. Effectively, he's a "Touch me and TPK" NPC, and doesn't need a CR.
If the goal is to eventually get to the point where the PCs can kill him, then you should pick a CR that you like, build him to that, and then tailor the campaign so that he's targeted when the PCs get to the point they can take that CR.