Railgunner: Annihilator

 is a challenge in Risk of Rain 2, added in the Survivors of the Void expansion. It is completed as by dealing 1,000,000 damage in one shot.

Completing it unlocks the in Railgunner's loadout.

Tips

 * It's advised to use when attempting this challenge, due to its extremely high innate damage potential.
 * Stacking and  can make this challenge trivial.
 * The damage itself does not need to be dealt with a M99 Sniper shot, it can also be dealt with other damaging items such as an, which can also be stacked for an easier unlock.