[1.2.320] Massive Buff

I think you misunderstood the charging time for skill, it works some sort like this.
lvl 1 - max charge time 2 sec
lvl 30 - max charge time 8 sec
Basically you accumulate more damage the longer you charge, a higher mastery just implies a higher cap so to speak.
I'm not too specific with the mechanics, but hope this general example clarifies things.

i understand wad u mean, wad im saying is that when comparing with other classes' 4th job skills: example genesis

as the lvl of the skill increases, the dmg output increases, the MP cost decreases (wad i will call user friendly as the lvl of the skill increases)

but for our assasinate, wldnt it make more sense to be charging for longer period at lower lvl of masterydoing not-so-high dmg while the charging time lessen while the dmg output increases as the lvl of the skill increases. (userfriendly, in this sense , is wad i meant)