Here is my Noor (at 3/70):
Note that her health is 1105.
I had full health on ALL my heroes with no reduction and Afrike hit me. This is the aftermath:
Noor’s health was dropped to 433. 433/1105 is not 70%. It’s 39.2% of her full health. Afrike should be only able to drop her max health to 774, right? Just to be sure it wasn’t graphical…I healed and she does top off at 433 (see last screenshot below).