spell dmg calculation

I cannot figure out how spell dmg calculation works. I am trying to make an optimal uppercut spam lootrunning build. what i don't understand is if I have a dps of about 3000 and uppercut dmg is 340% of your dps and my uppercut dmg is only 8000 how does this work.

the other question I have is if I have 291.90 – 433.69 water dmg in my melee attack and I put on water sanctuary a pair of pants that gives 90% water dmg and the water dmg of my melee attack only becomes 351.55 – 551.48 water dmg instead of an additional 90% of 291.90 – 433.69 which is 554.61 - 824.01

please help I can't make a good build without this information

 

Water damage is additive, not multiplicative. (I think.) It will not multiply your damage by 1.9x if you have 90% water damage. I found a old post, but it should probably help.

https://forums.wynncraft.com/threads/how-damage-is-calculated.176082/