Projectile doesn't go towards crosshair's direction!

Agressive? Never been agressive against someone who’s spending his time to help me =)

Look at this part of the video: https://youtu.be/cPr5K23Xk4c?t=4m9s

Why can’t I do something like this, using another FVector?

Is it mathematically impossible?.. seems incredible to believe… it’s just a third-part vector…