Alright, there is a thread in rules
here, which should clarify some things about Avoidant Spell and Circumventory Spell. In the mean time, I'd like to look again at King Solomon's Seal. We don't have a factor for calling unique entities anymore (it used to be +10). In fact, we actually lower the SP for spells that name a single individual! So that bit should be dropped.
The [call] seed has an interesting feature whereby you can try to trick the fiend into waiving its saving throw. This works best when the fiend's Wisdom bonus is much less than its saving throw bonus. If you have a 30 Intelligence and GSF in Conjuration you'll want the gap to be at least 15. Otherwise you are better off Heightening the Spell and trying to compel it to respond to your [call]. I think that anyone with King Solomon's Seal wouldn't resort to such trickery- it should provide a penalty to saves rather than (say) a boost to the CR that can be summoned.
[Call] now has a built-in period of 200 minutes of ordinary service. You'd need the [compel] seed to make the fiend do something it really doesn't want to do- like go into an
iron flask. Or perhaps not - this seems like something that the
minimus containment form of
binding would excel at.
I just realized that
binding is actually an epic seed. Simply change the casting time to one standard action from one minute (+4), waive the material components (500 gp + 500 gp/HD would be +4 or +5 for most fiends) and Heighten it to 10th level (+4) and you have a 10th level spell. I think I'll add it to one of our current threads.
Anyway, I'd say that King Solomon's Seal should provide a bonus to use of the [call] and [binding] seeds when dealing with fiendish nobility. It should provide a hefty penalty to the fiend's saving throws in the former case and a substantial boost to caster level in the second. Interestingly, these bonuses will generally not coincide; [call] doesn't allow spell resistance and so caster level is irrelevant; [binding], on the other hand, doesn't allow a saving throw (at least if your caster level is high enough) and so the saving throw penalty is irrelevant.
The requirement of Epic Spell Focus in the prerequisites is a real stinker. +1 to save DCs is pretty awful for a seed specialist who doesn't rely much on non-epic spells. Or one whose primary use of conjurations will be for effects that don't require saving throws. An epic spellcaster will be putting a lot of feats into Epic Spellcasting just to keep up with Matt. If Jake is going to spend two of these feats in pursuit of the secret of King Solomon's Seal, the results had better be pretty juicy; the equivalent of two specialized feats.
Actually, I'm wondering if that is too much. One feat specialized in fiendish nobility is probably enough; we don't need one that is double-powered. It might be better, I think, to tone it down, but drop some of the prerequisites.
And with regard to the skill-points; I can see that this is an "academic" feat that ordinary sorcerers (for whom Knowledge (the planes) is a cross-class skill) wouldn't be suited for. But I think if they pay the extra skill points they should be able to get it at a reasonable level; given that their intelligence will be much lower, it is a genuine cost to them. And I also think that if a cleric were to find these seeds associated they should be able to take advantage of the feat; requiring
greater planar binding as an arcane spell seems to be asking a lot. In fact, a religious element would not be at all inappropriate, given the namesake of the feat. Given the namesake, you wonder how it came about that he was casting all these [evil] spells. How about this:
King Solomon's Seal [Epic]
You can coerce fiendish nobility into service.
Prerequisites: Epic Spellcasting, Knowledge (arcana) 33 ranks, Knowledge (religion) 18 ranks, Knowledge (the planes) 18 ranks.
Benefits: You receive a +10 bonus to your caster level when you cast a spell incorporating the [call] or [binding] seeds against members of the fiendish nobility (such as demon princes or dukes of hell). Fiendish nobles receive a -10 penalty to any saving throw these spells may allow.
Special: A spell which benefits from King Solomon's Seal ceases to be a spell of the evil type.
Note: A fiendish noble usually has at least 20 hit dice, and is typically either an advanced member of a particular species (at least 50% more hit dice than a typical pit fiend, balor, etc.) or of a unique type.