Every hero in Tales of Radiance has one of the five elemental affinities: water, wind, fire, light, or dark. Each element balances each other out; water puts out fire, fire scatters wind, and wind evaporates water. Light and dark heroes beat each other out. If you have the elemental advantage, you deal 25% more damage and your accuracy is increased by 20%.

Additionally, there is also elemental synergy that you can take advantage of. There are multiple times of synergies, and we will list them all here.

All heroes of the same type (wind/water/fire): HP +22%, ATK +16%
Five light/dark heroes: HP +30%, ATK +20%
One hero of every element: HP +20%, ATK +12%
Four wind/water/fire heroes, one light/dark hero: HP +20%, ATK +14%
Three wind, two fire OR three fire, two water OR three water, two wind: HP +18%, ATK +13%
Three light/dark, two opposite element: HP +25%, CC RES +10%

If you are having trouble with a particular boss, take a look at their elements and see if you can use them to your advantage. You can even compose your team following one of the synergies listed above for an even greater advantage.