There are several skills in Vindictus that have a qualitative bonus when they reach rank 9. The following is an incomplete list of such skills and their respective bonuses.
Eagle Talon: allows creation of Magic Fire Mines.
Fury Infusion: cast is instant and the halting is removed if the user is running (not sprinting) at the time of activation
Guard: allows a perfect guard to count as the first two attacks in a combo
Magic Arrow: adds two smaller side bolts
Smash: Blossom Blow: allows an additional smash attack
Smash: Ivy Sweep: allows an additional smash attack which resembles a roundhouse kick
Fanning Slash: allows an additional shockwave smash attack
Standing Endurance: allows rolling out of a knockdown for a decreasing stamina cost
War Slam: Allows you to slam your pillar multiple times.
Battle Scythe: Demon Splitter: allows for a second smash attack