Power not working?

madmike82508

I am level 24 and ranked up'd chains of blazing light to rank 3, now it says plus 10% and 5's stun for rank 2 and 3, so wouldnt it be 20% dmg and 10 second stun? if so i only get about 4 second stuns on mobs..... stuns dont last as long with non regular mobs i am guessing but regular enemies it only last 4 seconds to, if im understanding this wrong sorry any help would be nice.

Also when upgrading powers you just add them right like 10% rank 2 10% rank 3= 20% increase in dmg?