I've played several games of DH, RT and DW but the issue of unnatural fellowship has never come up until I decided to create a serpent-tongued Slaanesh follower.

The bonus for unnatural strength/toughness etc. is very obvious, but what exactly does unnatural fellowship help with, other than being able to charm/deceive a few extra people in one go?

Unnatural now also gives extra degrees of succes on a succesful test equal to half the unnatural value.

Thanks for the reply. That's great, I didn't realise that. This is the only book I haven't purchased yet, so didn't realise there was a rules change.

No prob.

I forgot to mention, Fellowship Bonus also determines the maximum amount of minions you can have, and having that extra Daemonette, Murder Servitor can make all the difference.