EXTRA: Arma Dio Achievement in Vampire Survivors

Refer to EXTRA: Laborratory (5G) for unlocking this new stage. Then, load up the stage and head to one of the rooms along the top of the map behind the slide automatic glass doors. Inside, flip the lever(s) and an item will spawn. You're looking for the Arma Dio, which should come pretty easily. Grab it and you'll be given the option to pick any accessory. If you haven't already, get the Clover to evolve the Santa Javelin for that achievement.