Elemental Fusion in Gunfire Reborn allows you to mix elements on targets, resulting in different effects. Switching weapons and abilities quickly is rewarded with Elemental Fusion and the effects it will have on targets.
Explosion
Mixing the Burning and Decay damage will result in a powerful explosion that will damage surrounding enemies.
Handling
Shock and Burn damage will cause enemies to ignite their allies and fight them instead.
Miasma
By mixing Shock and Decay, you deal damage over time to enemies, which is very effective against health.
Elemental fusion is something you will need to practice on the fly. Because all weapons drop at random during a race, you can never be sure what items you are going to get, but it is important to consider what each weapon provides before picking it up. It is often more interesting to keep a lower level weapon if it deals a different elemental damage type, rather than carrying two weapons of the same damage type.
You can upgrade the weapons of any of the NPCs you come across while exploring a dungeon, so this can be a better way to improve your overall damage while still maintaining elemental diversity in your build. You can also choose upgrades as you level up that will increase your overall elemental damage, the subsequent fusion damage they can cause.
The two currently available characters also have different ways of enjoying the fusion in their kits. The Crown Prince Grenade can apply Decay to enemies, while Aoi Bai can take advantage of his dual wield ability to easily apply two elemental types without needing to switch weapons.
As the game is currently in Early Access, you can expect to see more characters added to the game, and possibly even more elemental types arriving in the future, so we'll update this guide accordingly when new ones. updates will arrive.