I’m not an expert on this stuff but I think I can at least clear up some things. This thread clarifies ele atk magic amp etc but I’m looking at the mechanics doc for the forumla (around page 15).
Let’s assume we’re only looking at 1 tick/line of damage.
First there’s the skill damage, or the base damage. Lv1 incineration is 553 base damage. If your character had 0 magic attack, 0% attributes, no ele dmg, no blessing, and the monster didn’t have any resists (I don’t remember if mag def applies here), then it would just be 553 damage.
I probably missed something but you get the idea. The base damage is the first number to look at.
Now, incineration is listed as a [Magic] type attack. This means that your magic damage will be applied accordingly. (1 hit, 1x your magic damage)
Because each point of int gives you magic attack, int will basically increase your incineration damage too.
However this is not the same as direct INT scaling on select skills such as Cure and Zaibas. Cure and Zaibas have their base damage value dependent on your int value (for cure it is 6 + 120% of your INT at lv1), and then will take your magic dmg into account again because they’re [Magic] type too. Incineration does not have direct INT scaling for base damage.
A good way to look at this is, if you drink an SP pot with a lv10 Chapparition card to get 10% magic damage, the magic damage that is added to your cure after the base damage will get that bonus, but your INT value that adds to the base damage will be unaffected because the bonus is magic damage% and not INT%.
The magic damage that comes from your INT stat still benefits from magic damage% though, so you can see how INT still comes into play even without any INT% buffs.
So far we have base damage + magic attack (if the skill is [Magic] type). Now, just add your elemental damage to that number. There is elemental resist, and it can modify this value, but I’m not going to go into that because I’m not entirely clear on it and it’s only really important if you want to buy hats.
Base damage + magic attack + ele damage
Magic amplification exists, so we have to account for that. What magic amplification does is adds bonus dmg randomised from 0% of the value to 100% of the value. What people like to do is just halve the magic amp and just pretend it’s free damage.
Now we get to attributes. It’s pretty easy, just take what you have so far, and multiply it by the attribute %. So:
(Base damage + magic attack + ele damage + magic amp / 2) * attribute %
Then add your blessing after attribute %. It’s important to remember that blessing is unaffected by damage enhance attributes, but things like ele damage still are.
With the 10% bonus for INT and STR for each rank beyond rank 1, INT adds quite nicely to true multihit skills like cure, zaibas, carnivory, owls and incineration.
As for predominantly non-magic builds, your main source of magic damage is definitely not going to include INT. In that case, your main source of magic damage will be the magic damage gained from levels (lv * 1), the magic damage off your mace (assuming you’re using one), and any buffs from your party. As far as I’ve read, transcendence doesn’t work on bonuses aside from the main stat of items, so the highest magic damage you could get from a non-lolopanther mace right now would be 303 from a catacombs club.
If you ask me, it might be great for rank 7, but at rank 8 it probably won’t do as much comparative to the new HP enemies have. It’s free damage but if you pick PD in a physical build you should make sure you’re either picking it for PvP or because you really want healing factor.
I think this video speaks for itself.