The draining sucks in a certain amount of damage then will close draining the troops power.
Lvl1 :drains 4% damage in 10 seconds.
Lvl2 :drains 6% damage in 9 seconds.
Lvl3 :drains 8% damage in 8 seconds.
Note : does not work on flying units
Note2: Does not damage troops just take away their power.
