NeoTun is a rare Runeword created by combining a Neo Rune of Ritual and a Tun Rune of Invocation.
How to Create NeoTun
You can create NeoTun by adding the rare Neo Rune of Ritual and the magic Tun Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Neo - Avoid health damage while fighting for 2 seconds. (200)
Tun - Invoke the Rogue's Stun Grenades, Stunning and dealing damage to enemies. (100)
Overflow
When NeoTun overflows, you receive the Tun Rune's overflow effect (Increased Grenades Spawned) 1 times.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.