SRD:Chaosbringer

Chaosbringer
This +6 greataxe of anarchic power grants its wielder the ability to fly into a rage (identical to a barbarian’s rage) once per day (or one additional time per day if the wielder already has the rage class feature). If the wielder has the greater rage class feature, the weapon also grants the wielder the Incite Rage epic feat.

Caster Level: 23rd; Prerequisites: Craft Magic Arms and Armor, Craft Epic Magic Arms and Armor, rage, mass charm monster; Market Price: 4,025,350 gp; Cost to Create: 2,012,850 gp + 50,250 XP.