Artificer: Massacre

 is a challenge in Risk of Rain 2. It is completed as by performing a multikill of 20 enemies.

A multikill is a streak of enemies killed; if a full second passes without a kill, the streak is reset.

Tips

 * Using a is a great way to gather enemies together and setup a big multikill. Combine it with several  for maximum effectiveness.
 * If you're able to survive, playing on a higher difficulty will scale the number of enemies faster, which can make getting multikills easier.