Initially planned to finish earlier today, the challenge seems to be extended for 6 more days. Even with fully-equipped tier 6 items, it's a tough challenge to get, but not impossible. With a friend, from 5 minutes when we were level 20 with tier 1 or 2, we reached 28+ minutes after reaching level 130+ and tier 6 equipment.
Last few minutes are insane, so choose the equipment carefully and save money to get lots of tier 6 gold packs. Stay close enough to your partner to revive him, use every statue you can, carry health potions... and both use Apollo. Do as many executions and double executions as you can, since they protect from arrows and replenish your health. Use rage only when necessary to save it for hard enemies or for going to revive your partner.