Like, really, why? It’s tailored for Necro’s skillset, or ok, maybe Shaman’s 2H stuff. I assume it has fire conversion but it still feels weird. I thought initially it was a bug, but empowered and mythic ones buff the same mastery and adds Nightblade, but never Necro. Was the thought process here like it would be too OP otherwise or smth?
Same reason why Vire’s Might has aether variation (which honestly will never see day’s light) - diversity. In fact, I was trying to theorycraft a Defiler with this weapon, but it’s a bit of a far stretch because outside of Gargabol pistol and Blightlord set vitality support for Demo is pretty much nil.
That’s why the weapon exists. Those items you mentioned are all items a Defiler can only use at Level 94 or 72 for the low level Epic Gargabol guns at a stretch (and these are still not that easy to come by). Revenant’s Edge and other items that support Vitality Demo exist because Defiler got harsh criticism during the AoM era that there was no easy or conceivably synergistic way to level it.
There’s already a lot of strong 2-handed Vitality weapons and support for Necromancer/Occultist/Oathkeeper/Shaman in other slots that you should look at over Revenant Edge.
Why? Because Zantai likes throwing down the gauntlet to see if people can make seemingly odd items work!