Missed opportunities.
So are the truenamer and shadow caster like Bruno? We don't talk about them?
Truenamer is legitimately the most broken class in 3.5e, which is a remarkable achievement given how bad 3.5e's design gets. However, unlike most broken things, it's broken because it genuinely
doesn't work. Like it is actually unplayable as written. You have to bend or even occasionally
break the class's own rules just to get something vaguely playable.
So, yes, Truenamer is Bruno, we don't talk about it.
Shadowcaster is just a somewhat pigeonholed themed caster, one amongst several in later-era 3.5e. It's not that we don't talk about it; it's that there's hardly much to talk about. Like the Dread Necromancer or Beguiler, it was
much too little,
far too late. Folks knew they could do better with just core classes, so the only people who went for these were the already-adventurous types.
I liked the idea that clerics would petition for spells, instead of simply taking them for granted. The problem (as I saw it) was that everyone treated this like it was at best a chore and at worst an invitation for the DM to screw you over under the auspices of your god punishing you for some religious infraction (something that shouldn't be done unless you were going out of your way to be heretical, i.e. your cleric of a healing god kept executing prisoners).
The way it should have worked (again, to me) is that your god trusted you enough to grant you the spells you wanted, but made sure to tailor your spell selection when they thought you might need a bit of a helping hand. So if the GM asked to see the player's character sheet, and then informed you that you didn't get those anti-undead spells you wanted, instead granting spells meant to fight demons, you were getting a helping hand from on high.
Well that's...sort of an unavoidable problem with this type of power?
Because what you're doing is
very literally telling the GM "Rewrite your divine casters' sheets whenever you like, however you like, as much as you like, and they aren't allowed to say no or even
complain lest they lose all of their abilities completely." That only works as a default, everyone-does-this thing when you can be certain that nearly 100% of GMs will use that power exclusively for good ends, or avoid using it at all.
I think you can see why that doesn't work. Even if only 20% of GMs abuse that power, it's 19.9 percentage points too many.