When do you unlock Shadow-Strike Branding? [Possible spoilers]

[Rogue]

So i'm replaying the game, i'm to the point where i'm branding the final warchief and realized that i still don't have the shadow strike branding ability yet when i remember from my previous playthrough having it.

I'm just wondering if i will unlock it before the final mission, if it unlocks after the final mission, or if i'm missing something.

[Donut Steel]

It's a Celebrimbor-only ability used in the Bright Lord story.

[Rogue]

Ohhh Okay. Thanks. I got so confused.

[Asha Man]

If you get bored and want a real challenge try this -

http://steamcommunity.com/sharedfiles/filedetails/?id=534822119