One very important thing: lurker, you shouldnt be the one making the sorcerer as you are trying to show that the beguiler wins. Let someone else do it...
I put one forth, the only thing they found wrong with it was it cast Feeblemind. My intent was, wait let me quote here.
See. Isn't that cute how the example Sorcerer choose as his one supper leet best in the universe 5th level spell a spell on the Beguiler list?
Isn't it cute to hear SorO brag about how his level 10 Sorcerer throws down leet Feebleminds to end encounters as proof of how awesome Sorcerers are?
*points to*
Extend/Persist can be done without Incantratix using Residual Magic and Cantrips but I just like the idea of adding save boosters to my example as a kick in the face to the fatespinner so I wanted the bonus feat slots and to do without Residual Magic. The feat selection sets up Spellsurge for double casting per round (and shapechange for 4 per round even later on) and the DC boosters mean it's better at save of suck/dies than the Beguiler build dependent on mind affecting abilities without the crummy once per day stuff.
So my posted build is better at save or dies, and has the versatility of being able to target the fort save instead of just will but got laughed out in an attempt to ignore it.
***
Back to what I was mentioning in my last post. Most of the Beguiler spell list is redundant. Take a look at the following.
1-color spray, hypnotism, sleep, whelm.
2-blinding color surge, daze monster, glitter dust, hypnotic pattern, stay the hand, touch of idiocy, vertigo, whelming burst.
3-deep slumber, halt, hesitate, hold person, slow, suggestion, vertigo field.
4-charm monster, confusion, crushing despair, mass whelm, phantom battle, rainbow pattern.
5-dominate person, feeblemind, friend to foe, hold monster, incite riot, mind fog.
6-mass suggestion, overwhelm, repulsion.
7-mass hold person.
8-demand, scintillating pattern.
9-dominate monster, mass hold monster.
What do they have in common? They are all save or suck/die vs will spells.
Versatility? Hardly, you get to pick what kind of effect happens when the target fails a will save, that's not the kid of versatility I care about. Who cares about debuffing different abilities, just go for death or domination and skip the rest. Anyone that can apply Heighten Spell on the fly can simply learn/prepare a target and area save or die effect and completely replicate or do better all of those spells at once.
Next, blur/displacement, (greater) invisibility, (greater) mirror image. None of those effects stack. If your blurry your clones are not, if your invisible being blurry isn't useful. Being invisible and having one clone pretend to be use is handy, though thats what the image spells, mislead, and arcane fusion are for. The only benefit knowing all of them is that you'll have some sort of miss chance against any foe missing True Sight if you correctly choose to cast the right one.
Another chunk of spells is simply the level up versions of lower level ones, like screen>nondetection>undetectable alignment, greater dispel>dispel, zone of silence>silence, ethereal jaunt>swift etherealness, silent/minor/major image, sphere/greater/mass invisibility, veil>disguise self, project image>mislead, and so on. While it can be useful to know multiple levels of virtually the same spell, it's not that huge of an advantage over someone that has the better one of each series.
Power Word Spells to the Beguiler are high level spells cast to kill weak CR 10ish foes as the Beguiler has no damage dealing spell. Well they have whelm. But that only works on a failed will save, so why not just go for a real save or die effect instead?
I don't think in any way a Beguiler is versatile. It has even less types of spells known than a Sorcerer when it comes down to it. And unlike even a Favored Soul, a Beguiler's offense is solely based on save or die spells that always target will. They can't even target someone's fort save, or deal damage, or buff the party outside of haste or invisibility. In combat the only thing you'll ever see a Beguiler is cast one of two party buffs, a self buff for a miss chance, a save or die vs will effect, and one of like 8 other spells(dispel, their warrior field thing, time stop, solid fog, umm... more save or dies). Out of combat, invisibility is great for the people lacking hide or daylight raids, so is every version of scry (expect scry it's self of course) for locating stuff you may have missed, the image spells always rock, glibness/charm person are handy for NPC interaction as well. I don't see how their out of combat spell list is versatile compared to a Sorcerer. Bluff+Cha is almost as good as glibness by the 10th level (+20) and most people learn greater invisibility and at least one image spell. As for being able to locate stuff, well you can't do absolutely everything as just a tier 2 class.
I think it's flat out required for a Beguiler to take Arcane Disciple multiple times to be useful just as a Druid must take Natural Spell or something and I've heard the beguiler spell list gets kinda meh after they get fifth level spells as well
. So 9th level on they keep falling behind everything else as the levels go on.