I assume you're playing on NAGC.
4th bar MP skills have just been released for certain characters on KGC; it will most likely take a while for them to release them on NAGC.
BRGC will probably get them first, since it's been like that for some "bigger" updates within the past already.
I guess you just gotta stay cool and wait, like we all do.
Trickster Online - Jewelia
Raiolo - Priest - 20x
Rubeius - Mercenary - 21x