Albion's new class is the Heretic, a Dark Priest/Evil Cleric class. It starts out as a member of the Church of Albion (as an Acolyte), but at fifth level renounces the Church and becomes an adherent of Arawn, the lord of the underworld who was introduced in the Shrouded Isles expansion. Heretics are able to use flexible weapons, but are restricted to cloth armor as well as small shields. As evil Clerics, they fit into the hybrid category, with both the use of combat styles and high-damage focus spells.

The Heretic's specialization spell lines are unique in Dark Age of Camelot. Where the cleric and friar classes have Rejuvenation baseline/Rejuvenation specline and Enhancement baseline/Enhancement specline spells, the Heretic will have Rejuvenation baseline spells and Arawn's Fire specline spells, as well as Enhancement baseline and Cthonic Accretion specline spells. This allows the Heretic to spec high in their offensive damage line, while receiving the benefits of a high Rejuvenation/Arawn's Fire spec for the Rejuvenation baseline spells. The Arawn's Fire spec includes single target and area effect focus damage spells. Strategically, that means the Heretic will start attacking a target, and while their damage will start off slowly, it will eventually ramp up over the course of 10-20 seconds to match that of a pure damage dealing caster. Arawn's Fire also has lower damage, uninterruptible versions of the focus damage spells, as well as a focus DD/Snare and an insta-cast snare for escape purposes. Rounding out the line is a twist on the basic resurrection spell where the Heretic can raise a dead realmmate - but as a horribly twisted creature that can do damage to enemies for a period of time before reverting back to normal form with only a small number of hit points remaining.