MoniXan is a legendary Runeword created by combining a Moni Rune of Ritual and a Xan Rune of Invocation.
How to Create MoniXan
You can create MoniXan by adding the magic Moni Rune of Ritual and the legendary Xan Rune of Invocation to a two-socketed 
Helm, 
Chest Armor, 
Pants, or 
Two-Handed Weapon.
Overflow
MoniXan 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.
Legions
Helltide