CirTal is a magic Runeword created by combining a Cir Rune of Ritual and a Tal Rune of Invocation.
How to Create CirTal
You can create CirTal by adding the magic Cir Rune of Ritual and the magic Tal Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Cir - Cast 5 Skills then become exhausted for 3 seconds. (300)
Tal - Invoke the Spiritborn's Pestilent Swarm, dealing damage to enemies. (30)
Overflow
When CirTal overflows, you receive the Tal Rune's overflow effect (Increased Swarms Spawned) 9 times.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.