I think that is a valid point as most of my Greyhawk knowledge comes from the ADnD Dugeon Masters Guide, Gord the Rogue and Mika the Wolf Nomad so obviously grain of salt and all of that.
So I dont know how legitimate it is to talk about Greyhawk underdark and then immediately start talking about Lloth and her Abyssal plane because yeah, of course the Abyss is going to be more evil then Forgotten Realms by definition but how does that compare Greyhawk Underdark with Forgotten Realms exactly?
And I dont know if a mass murder suicide catacylsm is really that evil considering that it happened years ago in the backstory and most likely consisted of probably two people firing Greyhawk Nukes at each other. I mean a cataclysm is a cataclysm whether it is caused by an arrogant High Priest or two warring countries or killing the Goddess of Magic. Even Earth has the Atlantians causing the great flood.
And I do not know how many points you get as a multiverse shaping Lich if the only things left behind are your Eye, Hand and Head. I mean full credit for the awesome backstory and killing an entire world has got to be great XP but really now you are competing with the Monkey Paw to be the most awesome body part artifact?
Again I am certainly no Greyhawk scholar and on the other hand even I can see the inconsistancies in the narrative.
The question was about evil though wasn't it...
Being prone to hubris and using powerful magic which causes a catastrophic accident (such as that which caused the Anauroch) isn't evil, it's egotistical to a megalomaniac level, but he intended to become a God, not kill everyone and destroy everything.
The Invoked Devastation and subsequent Rain of Colourless Fire in Greyhawk were deliberate annihilations of entire peoples and everything they had ever built. The first done to end a war based on the urges of Nazi-style racial supremacy, the second as an act of revenge carried out by Clerics whose God refused them deific vengeance, but which they undertook anyway.
The Underdark was a Greyhawk invention, so it makes no sense to compare them as it was plagiarised by FR. However, the Lloth in Greyhawk had far grander evil plans than the one represented in FR, and so I would argue she's a more cruel and megalomaniac version of the one represented in the FR Underdark.
I don't actually understand your point on Vecna... he became a demigod after losing his eye and hand to Kas... he then tried not to destroy a world, but the entire universe (see the Die Vecna, Die adventure module) with the purpose of remaking it from the darkness the way he wanted it with him as the only ultra-god. Annihiliiating everything that ever existed to remake the universe as entirely evil beats anyone's evil (except Tharizdun -
another Greyhawk entity...).
I raised the issue of evil artefacts because of their original provenance - check your DMG.
Sword of Kas - Greyhawk
Eye and Hand of Vecna - Greyhawk
Book of Vile Darkness - Greyhawk
Wand of Orcus - Greyhawk
Not to mention that the Demonomicon of Iggwilv (quoted in the Demons section of the MM) was written by Iggwilv (originally Tasha of the 'Tasha's Hideous Laughter' spell fame...). She is a Greyhawk character.
FR stole huge amounts of Greyhawk-defined evil;
Tiamat, Orcus (and nearly all the Demon Lords), Asmodeus (and nearly all the Arch Devils) to name but a few.
Greyhawk introduced the first soul-devouring weapon (Blackrazor) AND villain (Acererak), and has the most deadly dungeons in the game - even to this day. Tomb of Horrors anyone?
Even Acererak (once Vecnas apprentice) eclipses any scheme ever cooked up by Szass Tam in terms of pure evil - check out his ultimate aim in Return to the Tomb of Horrors to discover what that was.
Ultimately however, it is Wizards of the Coast who defined how much darker Greyhawk is than FR.
They classified FR as 'High Fantasy' and Greyhawk as 'Swords & Sorcery'. Their definitions of these being in the DMG.
S&S is darker and less heroic by definition than High Fantasy. Compare Lord of the Rings to Conan if you need a shorthand reference for that.
The foremost wizard who spends his time saving the world from itself and other threats is a concept also copied from Greyhawk. The difference is, Mordenkainen is much more morally ambigious than Elminster, and sometimes fights FOR evil, not against it.
In any case - I am now labouring a point that doesn't require any more illustration.
Greyhawk is simply a darker and more evil campaign world than Forgotten Realms.