Just for fun and for flavor, I want to dish out a little charisma damage to players that take a particularly bad beating. I seem to recall that there were some feats that allowed you to deal charisma damage, but now that I'm looking, all I can find is the Wolf style feat chain.
Anybody know about any others?
Well, there are always Tooth Fairies. But I don't know of a general feat for it, off the top of my head.
Have them all be part of a Reality Crystal Ball Show?
Bloodpyre and ungol dust both do Charisma damage; the latter also does a bit of Charisma drain.
It's a penalty rather than damage, but Paizo's version of ego whip might suit. The charisma damage from D&D 3.x's or from Path of War is closer, obviously.
The Leanan Sidhe has a touch attack that does CHA damage. I think technically as the CHA drain touch is a natural attack the Fey Shape spell would grant this.
If penalties are sufficient, there's always bestow curse. For that matter, you could probably convince most GMs that an equivalent amount of Charisma damage is "no more powerful".
Skull and Shackles Player's Guide has the following for battle damage:
This optional rules system gives GMs a way to assign scars and major wounds to their PCs. Before implementing this system, consider these rules carefully. Major wounds can have major effects upon play, and some groups may not appreciate such debilitations, preferring the threat of death and an unscarred resurrection over a thematic crippling.
These rules are a variation on the optional massive damage rule found on page 189 of the Core Rulebook. Whenever a character takes damage equivalent to massive damage, he must make a successful DC 15 Fortitude save or be reduced to –1 hit points and gain a permanent debilitating scar or handicap. These effects are randomly determined by rolling 1d20 on the table below. Effects are permanent and cumulative, though the GM should reroll results that seem too crippling or don’t make sense—such as a character losing a hand two or three times. The regenerate s pell h eals s cars and restores lost limbs, removing both positive and negative effects.
Rules for eye patches, peg legs, and prostheses to cover injuries and replace lost limbs may be found in Pirates of the Inner Sea.
d20 Battle Scar or Amputation
1–5 Minor scar—interesting but otherwise cosmetic
6–8 Moderate scar—cut on face (+1 bonus on Charisma-based skill checks for first scar only, consider subsequent cuts as a major scar)
9–10 Major scar—severe cut on face (–1 penalty on Charisma-based skill checks**)
11–14 Loss of finger (for every 3 fingers lost, –1 Dex)
15–16 Impressive wound (–1 Con)
17 Loss of eye (–4 penalty on all sight-based Perception checks)
18 Loss of leg (speed reduced to half, cannot charge)
19 Loss of hand (cannot use two-handed items*)
20 Loss of arm (–1 Str, cannot use two-handed items*)
* Losing a single hand or arm does not affect a spellcaster’s ability to cast spells with somatic components.
** At the GM’s discretion, characters with major scars may also be granted a +1 bonus on all Bluff, Diplomacy, or Intimidate checks against other pirates, as the scars of battle are much admired by pirates.
/cevah
Again, it's a penalty, not damage, but it could very well be what you're looking for.
Touch of idiocy. I'm partial to using it as a touch based trap. And apply metamagic feats.