YaxCeh is a magic Runeword created by combining a Yax Rune of Ritual and a Ceh Rune of Invocation.
How to Create YaxCeh
You can create YaxCeh by adding the magic Yax Rune of Ritual and the magic Ceh Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Yax - Drink a Healing Potion. (100)
Ceh - Summon a Spirit Wolf to attack enemies for 8 seconds. (100)
Overflow
YaxCeh can not overflow because the amount of Offering you receive from the Yax Rune exactly fills the required Offering of the Ceh Rune.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.