Mount Skill

ADD SKILL 

To teach skill 

open menu Mount

then open Skill tab

Klik "+" Button

Choose a skill then click Teach Button

or Click Level Up to level up a skill

btw you need fragment:mount skill to level up mount skill
you could recycle skill that you didnt use or need to get fragment

RECYCLE MOUNT SKILL
open Bag then Mount Skills

there a three button
left button to quick recycle (recycle many skill at once)
middle to recycle one skill
right to upgrade skill