Ok. I think this npc is from srv side :D if it's only in host..hm..then you could ask a gm(don't think will tell you :D)
Didn't managed to open dat file..
First you equip homu+acum you get acumen, then switch to shadow valhala(your homu will dissarm) and you will have m atk of valhala, but acumen effect will be there.
BTW this got fixed..at least doesn't work on gracia pt2 java
I voted for L2 couse it was the best mmo game ever ;D until new chronicles..secont place wow couse it's cool. I got bored from cs so he went third. And what is Aion? :D never heard of it.