YaxXan is a legendary Runeword created by combining a Yax Rune of Ritual and a Xan Rune of Invocation.
How to Create YaxXan
You can create YaxXan by adding the magic Yax Rune of Ritual and the legendary Xan Rune of Invocation to a two-socketed 
Helm, 
Chest Armor, 
Pants, or 
Two-Handed Weapon.
Overflow
When YaxXan overflows, you receive the Xan Rune's overflow effect (Cast increases damage by 1% per 10 Offering) 0.14 times.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.
Legions
Helltide