The
Challenger Rune can be unlocked be defeating the first boss named "The Concierge" located at
The Black Bridge.
To get to The Black Bridge, you must take 1 of 2 routes:
The Prisoner's Quarters -
Promenade of the Condemned -
Ramparts -
The Black BridgeThe Prisoner's Quarters -
The Toxic Sewers -
The Ossuary -
The Black BridgeThis boss isn't too bad. You'll want to use things like traps, turrets, and effects to take care of him. Keep an eye on your health, and dodge when necessary. Defeating this boss will cause him to drop the
Challenger Rune, automatically equipped as a permanent unlock, as well as unlocking an achievement.
https://www.trueachievements.com/a257070/the-fat-and-the-fur...With the Challenger Rune equipped you can now access Daily Challenges from the starting area or the main menu. The daily challenge is a competitive leaderboard mode finishing in a boss battle. Completing a run gives you progress towards unique blueprints and unlocks an achievement.
https://www.trueachievements.com/a257106/faster-than-light-a...