XolXan is a legendary Runeword created by combining a Xol Rune of Ritual and a Xan Rune of Invocation.
How to Create XolXan
You can create XolXan by adding the legendary Xol Rune of Ritual and the legendary Xan Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Xol - Invoke a Skill from another Class. (150)
Xan - Your next Skill cast will be a guaranteed Critical Strike and Overpower. (800)
Overflow
XolXan 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.