XolTun is a legendary Runeword created by combining a Xol Rune of Ritual and a Tun Rune of Invocation.
How to Create XolTun
You can create XolTun by adding the legendary Xol Rune of Ritual and the magic Tun Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Xol - Invoke a Skill from another Class. (150)
Tun - Invoke the Rogue's Stun Grenades, Stunning and dealing damage to enemies. (100)
Overflow
When XolTun overflows, you receive the Tun Rune's overflow effect (Increased Grenades Spawned) 0.5 times.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.