I finally got the Cenotaph to drop for me yesterday, and I gotta tell you - it’s a blast in PVE with coldheart and an ionic trace build. Double arc reserves and arc siphon with blinding explosions on my arc subclass is nuts! strong single target damage as well as crazy ad control, you’ve gotta try it if you happen to have the helmet.
You have to get it from the lost sector on ‘head day’ the first time; after that I believe it gets added to your world drop pool.