Thundersoother

Thundersoother adds damage against opponents affected by Electro. The two-piece bonus only raises Electro resistance, which helps you survive certain Electro-heavy bosses and areas but adds nothing to damage. The four-piece bonus is a sizable damage boost, but only while the target has Electro applied.

In practice, other sets with damage or reaction bonuses usually do more, so this one rarely sees use. It can work as a stopgap for an Electro character who keeps Electro on the target themselves, or for a damage dealer in a team that applies Electro constantly.