Resonance is the increase of a character's Tier. Resonance can change the skills and increase the character's stats.
There are 4 tiers in total, N, R, SR, SSR. At tier SSR, the character can further resonate 10 more times to increase their stats, but their skills will not change.
This summary shows the number of materials required for the resonance of Ned as an example. This summary isn't accurate for every character. In order to know the proper resonance materials, please refer to individual character pages.
The region material needed for resonance depends on the character. A list of region materials, as well as the quantity needed for resonance, can be found below. For the region material specific to the character, check out the character page.
The character mineral specific to the character is also needed for resonance. Do note that SP characters do not share the same character mineral with their normal forms - their character mineral has a red illustration while that of the normal characters' are in blue.