UrOno is a magic Runeword created by combining a Ur Rune of Ritual and a Ono Rune of Invocation.
How to Create UrOno
You can create UrOno by adding the magic Ur Rune of Ritual and the magic Ono Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Ur - Your Minion or Companion kills an enemy or dies. (10)
Ono - Invoke the Druid's Dancing Bolts, seeking and dealing damage to enemies. (25)
Overflow
When UrOno overflows, you receive the Ono Rune's overflow effect (Increased Bolts Spawned) 0.2 times.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.