A while back on pfsrd I know I saw a negative energy channeling feat that did something like make enemy shaken if they failed their save, but now I can't find it at all... I think one of the prereqs was having Lamashtu as your patron deity. Anyone know what feat I'm talking about?
Iunno.
I found this in my search, which was pretty cool.
The Madness Domain is a 30 ft radius of Confusion, which is kinda sorta not really what you were looking for.
This lets you stagger people on a crit, so closer I guess.
Wait: BINGO!
The SRD is inconsistent on this though, the main page says Urgathoa but the General Feats page says "Worshiper of an Evil god".
Either way, not Lamashtu specific.
Yeah it might have been Urgathoa, but for some reason Lamashtu was stuck in my head... Hmm I'll look again with that in mind, but I seem to remember the feat in question giving the shaken condition to enemies that failed their save vs a negative energy channel.
Edit: Found it. Knew I wasn't crazy! Yeah, it said Urgathoa on the actual page but only says an evil god is required on the main listing. I searched for "channel" on the general feats page before coming here and I somehow completely missed it twice >_<. Thanks for input guys.