NocTon is a rare Runeword created by combining a Noc Rune of Ritual and a Ton Rune of Invocation.
How to Create NocTon
You can create NocTon by adding the rare Noc Rune of Ritual and the magic Ton Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Noc - Inflict a Crowd Control that isn't Slow or Chill. (5)
Ton - Evoke the Sorcerer's ites, dealing damage to enemies. (25)
Meteor
Overflow
NocTon can not overflow because the amount of Offering you receive from the Noc 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.