Heustess was a minor character in Geneforge 1. Unlike the spirits and rogues which inhabited the wastes and ruins west of Sucia Island, he was a tiny warped humanoid shrouded in dark robes, armed with a crystal plate and imbued with great magical powers, such as shaping shades and a vampiric touch which drained the endurance of a character.
He reigned over the Sentinels for years until he was presumably forced into servitude by Goettsch, whom he hated enough to offer a pact with the Shaper apprentice abducted by Trajkov.
When spoken to, Heustess reveals that he was given his powers when he was warped and twisted by the magic of the enemy of his people. This crude alteration of life seems to imply that these were proto-Shapers, and that Heustess himself is the sole remaining witness to the rise of the Shapers as a people. This is never expanded on in later games, and left only to speculation.