MoniTal is a magic Runeword created by combining a Moni Rune of Ritual and a Tal Rune of Invocation.
How to Create MoniTal
You can create MoniTal by adding the magic Moni Rune of Ritual and the magic Tal Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Moni - Cast a Skill after moving.
(Cooldown: 0.25 seconds) (25)
Tal - Invoke the Spiritborn's Pestilent Swarm, dealing damage to enemies. (100)
Overflow
MoniTal can not overflow because the amount of Offering you receive from the Moni Rune exactly fills the required Offering of the Tal Rune.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.