CirTon is a magic Runeword created by combining a Cir Rune of Ritual and a Ton Rune of Invocation.
How to Create CirTon
You can create CirTon by adding the magic Cir Rune of Ritual and the magic Ton Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Cir - Cast the same non-Channeled Skill 3 times in a row. (25)
Ton - Evoke the Sorcerer's ites, dealing damage to enemies. (25)
Meteor
Overflow
CirTon can not overflow because the amount of Offering you receive from the Cir Rune exactly fills the required Offering of the Ton Rune.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.