If the Golden Gear has been picked up and not lost he will only attack once, before rapidly making his way back towards the lava pool with the waterfall and jumping in. After a few seconds, three rakk will then fly in and each drop a Hyperion loot chest; two are normal, while the middle one always contains purple or E-tech loot just like the chest in Sanctuary. These crates will only appear once, when the mini-quest is completed.