well on the vid and gif you placed, whenever you faced to the right (assuming enemy always appears on the right) and attacked, the slash animation is used
however the animation itself is a slash to the left,
the animation is fitting when you face to the left but looks slightly out of place when attacking when facing right, hence why I was suggesting
inverting the animation's direction when facing right, and keeping it normal when facing left, but yeah I'm not sure how you have the battle system set up
so it's up to you,