* Element (e)
Ele_Dark, Ele_Earth, Ele_Fire, Ele_Ghost, Ele_Holy, Ele_Neutral, Ele_Poison,
Ele_Undead, Ele_Water, Ele_Wind, Ele_All
Atk/Def
-------
bonus bAtkEle,e; Gives the player's attacks element e
bonus bDefEle,e; Gives the player's defense element e
https://github.com/rathena/rathena/blob/master/doc/item_bonus.txt