"How is Concussion Blow's effect determined?"

Concussion Blow's damage is the absolute value of the victim's current mana percentage minus their current hit point percentage, divided by four, plus ten. (Absolute value means that the result is treated as positive - see examples below.) However, the damage bonus will be at least ten and not more than 30.

Example: Your opponent has 90% of their mana remaining, but only 40% of their health. Concussion Blow subtracts 40 from 90 to get 50%, divided by four is 12.5. The decimal value gets dropped, plus ten is 22. That's within the allowable range, so your move will do 22 extra damage.

Example: Your opponent has only 40% of their mana remaining, but 90% of their health. Concussion Blow subtracts 90 from 40 to get -50%, converts that to absolute, divided by four is 12.5. The decimal value gets dropped, plus ten is 22. So the end result is exactly the same as above - it's the difference between HP and mana which matters, not which one is higher.

Seems like a good tag-team combo (mage/warrior) where you could maybe mana vamp then the warrior concussion blow as a opening volley but you have to be quick on high resist foes?