RNG boss is RNG (phase 2), when luck is with you, it's pretty easy even with 1 watcher, 0 is really hard though, probably even impossible. In this kill he actually bugged out near the end, so he didn't cast Lunatic Gaze. It's without a doubt I would have killed him anyway, in fact, it probably hurt more than it helped, as I was afraid to face him (4 sanity left because phase 2 is sooo clear of bugs... or something)