I often hear people swearing by Howling Wolf Tattoo (and putting it on Vanessa), but I haven't really figured out how to use this one. The few times I have taken it I haven't used it, so I don't even take it anymore. Giving somebody 'Sister' just seems highly situational. It can give melee expert to a beatstick, but that's just exchanging 1AP for another, so highly situational. Aside from that, having the sister buffs on such a beatstick can certainly boost the damage anywhere on the board, but to take advantage of that I'd have to activate the Viks early in the turn which I usually don't want to do unless they're about to get smashed.
So all I can see is that it looks highly situational, and being so I can't see that it's worth the SS cost and upgrade slot.
I know there's something about not discarding a card to flurry, but given I'd just discard a low card anyway I'm not sure how useful this one is either...
So, what am I missing? How is everybody using this one?