YulTec is a legendary Runeword created by combining a Yul Rune of Ritual and a Tec Rune of Invocation.
How to Create YulTec
You can create YulTec by adding the legendary Yul Rune of Ritual and the magic Tec Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Yul - Cast a Skill with a Cooldown. (50)
Tec - Invoke the Barbarian's Earthquake, dealing damage to enemies within. (100)
Overflow
YulTec can not overflow because the amount of Offering you receive from the Yul Rune exactly fills the required Offering of the Tec Rune.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.