Remathilis
Legend
The 2E Athasian Bard was not a spellcaster, they rewrote it because magic is hard. The PHB Bard was a spellcaster, on Darksun it was not.
In 5E terms it would be an Rogue:Assassin with the perform skill and poison use.
You were talking about Greyhawk in the quoted text, not Dark Sun. I think you're mixing your terms.
Themes are not used to club people into submission.-
They are when they are used to arbitrarily nerf PCs.
I'll give DS a break for a moment. Ravenloft tries to keep a theme of "horror" going with its rules. It does so by intentionally nerfing a lot of abilities that either confront undead (turn undead) or help give away the plot (divinations). As the setting progressed through, more and more things were used to club PCs who thought to use them as advantages. Animal Companions and Familiars betrayed their masters. Resurrection magic faltered, healing magic had a chance of failing. Almost any magic used to harm someone required a Power check (not just necromancy). Domain Lords routinely could ignore the PCs efforts with impunity. It could get so bad that it felt railroaded; do what the DM says because "the Mists block every other option".
One of the tropes of Gothic Horror is a sense of powerlessness, I get that. But when it get so bad that most PCs can't perform their class functions, you might need to dial back the "theme" a bit.
Which is my point; if the rules require I be near useless and most of primary tools (be it magic, weapons, or class functions) be removed or nerfed to keep the theme, its time for the theme to dial back some.