Did some lab work in the tavern with a squire. What I've found is that physical damage upgrades to 1.15 of previous damage. Elemental upgrades to 1.20 of previous damage. Physical upgrades seem to cap off at 80 per upgrade whereas elemental damage seems to be capped at 300ish.
As a general way of estimating weapon damage for upgrades:
- For physical damage, every 5 upgrades doubles the amount
- For elemental damage, every 4 upgrades doubles the amount
A 50 base physical weapon with 20 upgrades will end up at roughly a final stat of 800 (818 to be exact).
Damage per hit depends on your class and the attack stat of your character.
For the squire, the 2nd strike in the combo is at 1.20 of the base damage, 3rd and 4th are at 1.40.
I'm currently unsure of how hero strength factors into this. I originally thought it was .03 phys damage added back per point, but that is mistaken. My weapon of 432 on a squire with 46 str does 848 dmg which is 1.962 repeat damage, divided by my str thats a modifier of 0.042 added per Str point, but my squire with str 74 and sword 58 dmg is doing 129 so 2.224 damage, which when divided by str is 0.03 per point.
I'm assuming that each str point has less of an impact on a curve but the formula I don't know.