MoniTun is a magic Runeword created by combining a Moni Rune of Ritual and a Tun Rune of Invocation.
How to Create MoniTun
You can create MoniTun by adding the magic Moni Rune of Ritual and the magic Tun 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)
Tun - Invoke the Rogue's Stun Grenades, Stunning and dealing damage to enemies. (100)
Overflow
MoniTun can not overflow because the amount of Offering you receive from the Moni Rune exactly fills the required Offering of the Tun Rune.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.