Alter Ego: Brendan Rathcoole
First Appearance: Warheads #2 (July 1992): "The Trouble with Pellis Globus"
Super? (Has Super Powers/Special Abilities/Technology): Yes
Number of Appearances: 22
Rathcoole was a Mys-Tech Techno-Wizard and a head of the Warheads. The Techno-Wizards are identified as a "former cult of Druids [who] gained power and immortality from Mephisto in 987 A.D. in exchange for wreaking havoc on Earth. [They] went on to form board members of Mys-Tech."
Another source refers to this group as an "ancient Druid sect." Given the nature of these Techno-Wizards, it seems doubtful that they are best classified as "former Druids." It appears that they continue to be Druids who seek to use mystical Druidic power to further their own ambitions, but that they are heterodox from traditional Druidism, their sect having been corrupted by their centuries-old pact with Mephisto (the Devil).
Suggested links for further research about this character and the character's religious affiliation: