The chapter "Tradition and Anti-Tradition" from Rivolta refers several times to the founder of Zaroastrianism, and is therefore indirectly related to Manicheistic related ideas, the Magi were seen as overly moralistic priests.
The "Mystery of the Grail" book deals with the idea that the Albigensians were holders of a more sacral and royal Ghibbeline tradition than the Catholic-Guelph faction.
If there is a more direct reference in his work, I apologise for failing to locate it at this time, however, with Evola's positive views of Zartusht, Albigensians, and the Hermetica I think we can deduce that he wasn't hostile to the demuirge idea.
From: emmanuelparapine <emmanuelparapine@...>
To: evola_as_he_is@yahoogroups.com
Sent: Saturday, October 8, 2011 10:30 PM
Subject: [evola_as_he_is] Julius Evola and manicheism
What did the Baron write about Manicheism and especially about its fundamental dogma (opposing the luminous and divine soul and the dark and evil matter, by which the first one is imprisoned)?