Server - Arcane Sanctuary
Direct message me and tag me in a comment so I get notified and we can set the run up fast that way.
Level 40 duo challenge rift completed within timer - 375 fg
Level 50 duo challenge rift completed within timer - 625 fg
You can afk at the entrance, or follow behind me at a distance so you don't agro mobs.
Tagging the boss with an attack is fine and will guarantee you a few levels in most cases.