For me, I'd like it to stay as a self-only spell and still be melee only like it is now, but I'd like to change the vulnerability. The current vulnerability is that it's an Enchantment with a long recast, although when I think of the advantages... it ignores Blind, stances... it's actually a bit weird really isn't it?
Well ok, how about a totally new skill like Theos says that is a mesmer Weapon Spell that gives you glowie melee weapons, has all the vulnerabilities of normal weapons (Blind, stances and so-on), but does Chaos damage instead of Slash/Pierce/Blunt? A bit like... Judge's Insight I suppose.
I can't decide if it should just convert the damage type to Chaos, or if it should bypass armour or add 20% armour penetration... I think it should still be 'self only' though, so no casting it on barrage rangers etc!
A Me/Rt with Wielder's Boon could be a possible combo, just to throw out another idea.
Again, just raw ideas.