Hefaetrus is the Amazonian god of fire and rebirth who lives deep within the great volcano, Mount Arnazeus, on the island of Philios. Although primarily the patron deity of farmers, from time to time he bestows his favors upon the warriors of the Islands, so they may keep safe his congregation. Hefaetrus is also husband to the Amazonian god Zerae.

Hefaetrus is the source of power behind the following Diablo II Amazon skills:

Fire Arrow
Exploding Arrow
Immolation Arrow

Description and more information on these skills could be found in the Diablo II Amazon Bow and Crossbow Skills page.

Reference

Diablo II Manual