It seems to only calculate the damage caused by the surface (not the multiplied damage), maybe 1DMG=1pt(?), so only 1x DMG can be used, ex. 200Lv pt is about 1.1 million~1.2 million ?(SOLO)
So if you want to pass the level quickly, choose the one that is close to your combat power, otherwise you can only wait patiently for it to fight slowly (or choose fire attribute skills to be much faster)
The above is GOOGLE translation, please forgive me if there are grammatical errors