http://www.4shared.com/file/16576321/7e7149e3/itemname-e.html
We'll start with the sql and XML files and then the client side. In weapon.sql go to dusk sword ID (5800) and replace it with this (don't forget to run weapon.sql again in navicat):
(5800, 'Dusk Sword', 'rhand', 'true', 1300, 1, 1, 'adamantaite', 's', 280, 10, 'sword', 8, 0.00000, 0, 0, 0, 379, 0, 180, 95, 0, 2440, 'true')
In the XML file in gameserver>data>stats>weapon>5800-5899.XML replace your dusk sword weapon values with this:
<item id='5800' name="Dusk Sword Acumen">
<for>
<set val='280' order='0x08' stat='pAtk'/>
<set val='180' order='0x08' stat='mAtk'/>
<set val='4' order='0x08' stat='rCrit'/>
<add val='4' order='0x10' stat='accCombat'/>
<set val='379' order='0x08' stat='pAtkSpd'/>
<enchant val='0' order='0x0C' stat='pAtk'/>
<enchant val='0' order='0x0C' stat='mAtk'/>
<!-- SA: Acumen -->
<mul val='1.15' order='0x30' stat='mAtkSpd'/>
</for>
</item>
On the client side you have to replace your dusk sword (ID 5800) with this in weapongrp.dat:
0 5800 1 1 7 10 0 LineageWeapons.duskk_sword_m00_wp LineageWeaponsTex.duskk_sword_t00_wp icon.weapon_sword_of_miracle_i01 95 1380 1 1 0 7 1 1 LineageWeapons.duskk_sword_m00_wp 1 LineageWeaponsTex.duskk_sword_t00_wp 4 ItemSound.sword_small_1 ItemSound.sword_great_4 ItemSound.sword_mid_2 ItemSound.public_sword_shing_4 ItemSound.itemdrop_sword ItemSound.itemequip_sword 10 280 180 1 5 8 0 0 0 0 379 0 1 1 1000 0 -1 0 LineageEffect.c_u006 2.00000000 0.00000000 0.00000000 1.00000000 5.50000000 LineageWeapons.rangesample 3.29999971 1.00000000 1.00000000 15.00000000 1.00000000 0.00000000
Credits to my friend Solution[again!!!] and petru!!!