So i was doing some research about twin blade builds/skills and stuff. But a couple of skills that are mention i have yet to see on any weapons. These being; Misty Massacre, and collapsing blade. I just wanted to know if I'm just really unlucky or if those were part of a content update that isn't included with ps4 version

You're just unlucky. Collapsing Blade is a skill in the game from the start and you did not mention Crag Thrust which was included with the update that has Misty Massacre.

I haven't seen crag thrust either, but I wouldn't doubt that I'm just unlucky. Thanks for the reply