Skill Unlock Pack question

Hello, I recently purchased the Skill Unlock pack for Core skills. It has unlocked the Hundred Blades elite skill which I'd like to use for my Warrior but I don't know where to find it, it says it is offered by a trainer but the ones I currently have available to me do not offer it.

I am on Nightfall as a Warrior in the Sunspear Sanctuary. Any information is greatly appreciated.

Thank you.

With elite skills, you gotta capture them. You will never be able to buy an elite skill at at trainer. You'll need to buy a signet of capture from a skill trainer and go cap it. You can cap it from the [wiki]Reaper of Agony[/wiki].

or buy/find an elite warrior tome to use to get it since the skill is unlocked on your account

Thank you both for the info.