CirXal is a rare Runeword created by combining a Cir Rune of Ritual and a Xal Rune of Invocation.
How to Create CirXal
You can create CirXal by adding the magic Cir Rune of Ritual and the rare Xal 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)
Xal - Gain 20% Maximum Life for 6 seconds. (200)
Overflow
CirXal can not overflow because the amount of Offering you receive from the Cir Rune exactly fills the required Offering of the Xal Rune.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.