Pause

Pause is a challenge in Risk of Rain 2. It's objective is to "Free the survivor suspended in time".

How to Complete
Start by collecting eleven1 Lunar Coins. This may take time but should not be too difficult since Lunar Coins persist between runs.

Next, find and activate a lunar shrine(newt shrine), which can usually be found in the second world. This cost one Lunar Coin. A prompt "A blue orb has appeared" should pop. After charging the teleporter and defeating the boss, a blue portal appears next to it. Interacting with the portal takes you to the "Bazaar Between Time".

Finally, in the Bazaar, interact with the crystal next to the giant newt. This costs 10 Lunar Coins and is labeled "Free the survivor". This completes the challenge and unlocks the Artificer.

Do note that in multiplayer lobbies, only one player can complete the challenge and unlock the Artificer at once.

1 - Since the Bazaar portal also has a chance to spawn in randomly, a minimum of 10 lunar coins is required to unlock the Artificer.