Ranged Backstab

If I wanted to add a Special Ability to a custom Player’s Companion character allowing it to use the Backstab multiplier with ranged weapons (as long as the target is unaware, that is) in addition to the standard backstab, how many Special Abilities will it cost? I was thinking about three but maybe less?

Another option I’m toying with is making Sniping (AKA ranged backstab) a Thief skill which could be selected when designing the class, just like any other skill.

What do you think?

Not an Autarch, but: Sniping class proficiency (core ACKS, p. 63) does this for anything up to short range. And a class proficiency, a thief skill, and a custom power are all essentially 1:1:1 equivalent in the Player’s Companion.

Many thanks! Missed that in my previous read-through!