if that is so then why do the black templars use them arnt they strictly agienst anyone using or seeing into the warp?
Yes.
No.
I'm not sure...explain below.
if that is so then why do the black templars use them arnt they strictly agienst anyone using or seeing into the warp?
Those who judge without reason are no better then the things they judge.
In their codex they use astropaths and navigators out of necessity, but exclude librarians.