Hello, as the example
// Examples:
// MC_MAMMONITE,BL_PC,1,50 // In normal maps, players deal +50% damage to other players with Mammonite.
// MO_EXTREMITYFIST,BL_PC,6,-50 // In PVP and GVG, players deal -50% (half) damage to other players with Asura Strike.
// AB_ADORAMUS,BL_PC,6,50,0,10,15 // In PVP and GVG, players deal +50% damage to other players, +0% to mobs, +10% to bosses, and +15% to other with Adoramus.
https://github.com/rathena/rathena/blob/master/db/skill_damage_db.txt
see the adoramus lines, that might help a lot.