Xol's back baby!
A few people noticed something strange happening on Io when starting a Taken Blight public event. A secondary boss can spawn away from the public event area, and upon killing it, a taken portal will appear in the area.
Through there, things get weird. Take your jumping puzzle hats and best add clearing weapons, because you'll need them to complete the mission in 20 minutes.
Your reward? Whisper of the Worm - a sniper rifle that is, to all intents and purposes, pre-nerf Black Hammer from D1. Polygonal rifling, ammo generated from thin air on precision shots, it's all there, and with a hefty lore tab too. And that's not to mention the catalyst that'll grant the Box Breathing trait too (as found on the IKELOS sniper).
I'll be spending tomorrow (Saturday) having a crack at this. Full fireteam and patience is definitely needed.