CemMot is a rare Runeword created by combining a Cem Rune of Ritual and a Mot Rune of Invocation.
How to Create CemMot
You can create CemMot by adding the magic Cem Rune of Ritual and the rare Mot Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Cem - Cast Evade. (75)
Mot - Gain 1 |4 shadow:shadows;, from the Rogue's , reducing damage taken per shadow. (150)
Dark Shroud
Overflow
CemMot can not overflow because the amount of Offering you receive from the Cem Rune exactly fills the required Offering of the Mot Rune.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.