TamQua is a legendary Runeword created by combining a Tam Rune of Ritual and a Qua Rune of Invocation.
How to Create TamQua
You can create TamQua by adding the legendary Tam Rune of Ritual and the rare Qua Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Tam - Cast a non-Channeled Core Skill. (25)
Qua - Restore an Evade charge and gain 6% Movement Speed for 5 seconds, up to [6*5]%. (400)
Overflow
TamQua can not overflow because the amount of Offering you receive from the Tam Rune exactly fills the required Offering of the Qua Rune.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.