The book was not specific on this so I kinda got lost. The Orbius example in the book (YS p. 294) uses 3 shifts for effect and 2 shifts for duration. It chokes (Grapples) the enemy and does 1 point of stress per exchange.
If I cast Orbius on an enemy with 8 shifts on effect and 2 shifts on duration how much damage will Orbius do per exchange?