CirXan is a legendary Runeword created by combining a Cir Rune of Ritual and a Xan Rune of Invocation.
How to Create CirXan
You can create CirXan by adding the magic Cir Rune of Ritual and the legendary Xan Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Cir - Cast the same non-Channeled Skill 3 times in a row. (50)
Xan - Your next Skill cast will be a guaranteed Critical Strike and Overpower. (800)
Overflow
CirXan can not overflow because the Xan Rune does not have an overflow effect.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.