Resonance Disc

The Resonance Disc is a Rare item in Risk of Rain 2. When the player with a Disk kills enemies spin is generated, which in turn charges the disc, and once it is fully charged, it launches itself at enemies, dealing heavy explosive damage. Spin decays quickly between kills, but charge does not, so the Disc will fire eventually, even if the player does not kill enemies rapidly, as long as they kill them.