When having Ren's Fury activated (+10 damage) and using might, the damage shown when pointing the attacks to target is (DMG + Ren's Fury) * Might, but the damage applied is actually DMG * Might + Ren's Fury
Example: After having ren's fury activated and trying to use Spirit Rend with might, the damage was shown as 44, but 41 was applied. Same happens with Ult (didnt try the other skills)