Or, how does Fear, Insanity and Corruption really work in DW?
"And they shall know no fear"... has been taken to the extreme. Space Marines in DW are not affected by Fear as mere mortals - instead of rolling on the Shock Table or gaining Insanity points from failed Fear tests, they either get -10%(fear rating) to WP tests in Solo Mode, or risk losing Cohesion if in Squad Mode.
Not that is all well and good when facing Nids, but what does this actually mean? When does a typical Space Marine need to make WP tests? Does this affect the Librarian's Focus Power tests? How does the Space Marine gain IP and CPs? And they are not immune to those even if the effect on their psyche is very different than from normal humans...
It seems odd that the character that is most affected by the Daemons and horrible Xenos are the ones often used to combat them - Librarians. Sure they often have good WP too, but that penalty in Solo Mode is harsh as it affects all their Powers, potentially reducing them to normal space marines again.
Also, how does Space Marine react to weird happenngs, Warp incursions, Haarlock stuff, cosmic mind numbing horrors of doom.. well you know, those that normal mortals go batshit crazy for? They might be used to fighting ugly things that makes normal people in catatonic states, but I'm talking about the stuff that makes Inquisitors cry and renounce the Emperor...
So for the most ultimate horrors of the galaxy - what gives? The rulebook says only "The GM decides" but I would like some guidelines on this, or some hint of mechanics. This applies to Fearless characters from DH and RT as well.