Upgrade hero skills

[NoonyCurt]

Beginner's question: How do I upgrade hero skills?

Some skills say something like 0/30 <fire symbol>. How do I add fire?

[Thunder]

for your example: you apply Fire elements to equipped items for that hero (each hero can hold 6 items).

If you are just starting then get the first level of fire which will give 5 points each for a total of 30. All other elements do not help that particular hero.

As you level up, there are higher tiers of elements that you can apply (10 each and 15 each).

[NoonyCurt]

So the skills are not permanently upgraded, but depend on constantly equipping items with fire element?

[Thunder]

yes
(though you will always have at least the level 1 of the skill if you don't have any/enough fire element)

[NoonyCurt]

Thanks!