Zamorak bow
From Emps-World Wiki
The Zamorak bow is one of the best bows in Emps-World, as well as the Saradomin bow. It is the only bow that can use Zamorak arrows, which are better than Dragon arrows when used in combination with this bow, because they give an additional effect with every arrow that damages your target anywhere between 1 and 4 damage. It requires 80 Range to equip.
It can be obtained as a rare drop from K'ril Tsutsaroth in God Wars dungeon.