Okay, folks, so I looked for a custom warlock/binder prestige class for a little while, and couldn't find one I liked, so I thought I'd try my own hand at creating one. It's based loosely on the Anima Mage PrC, but I made a few substantial changes that I thought were in balance with the rest of the game. Let me know what you think!

The Eldritch Pactmaster

The combination of being a product of a supernatural pact made by one of your ancestors and your experiences continuing this tradition with the forlorn vestiges of the void have made you an expert at striking deals with otherworldly entities. Perhaps you were drawn to soul binding as an avenue for understanding your own nature; perhaps you discovered that nature through your experiments binding vestiges. Either way, you are more than simply talented at pactmaking—you are a master.

ENTRY REQUIREMENTS
Skills: Bluff 4 ranks, Diplomacy 4 ranks, Intimidate 4 ranks, Knowledge (the planes) 8 ranks
Feat: Skilled Pact Making
Special: Ability to bind 2nd-level vestiges, eldritch blast +2d6

Invocations: At each level, you gain new invocations known and an increase in caster level and eldritch blast damage as if you had also gained a level in the warlock class. You do not, however, gain any other benefit a character of that class would have gained.

Soul Binding: At each level, your soul binding ability improves as if you had also gained a level in the binder class. Your eldritch pactmaster levels and binder levels stack for the purpose of determining your bonus on binding checks, the effectiveness of your vestige-granted abilities, your ability to bind higher-level vestiges, and the number of vestiges you can bind. you do not, however, gain any other benefit a binder would have gained.

Master Pact Making: At 1st level, you gain a +4 bonus to your binding checks to bind vestiges. This stacks with the bonus from Skilled Pact Making.

Supernatural Blast (Su): At 2nd level, you can use a bound vestige to augment your eldritch blast by temporarily giving up access to its powers. Using supernatural blast is a swift action that does not provoke attacks of opportunity.

Choose one of the vestiges to which you are bound whenever you activate this ability. You lose access to all the abilities and powers granted by the chosen vestige upon activation and do not regain them for 5 rounds. You can then transform any eldritch blast you cast that round into a supernatural blast. A supernatural blast does damage equal to your eldritch blast, and still requires a somatic component to cast, but is in all other ways considered a supernatural ability rather than a spell-like ability, and thus is unaffected by spell resistance and spells such as minor globe of invulnerability and spellturning (but it can still be nullified by an antimagic field). You may apply eldritch essences and blast shapes to your supernatural blast the same as you could for your eldritch blast. You cannot use this ability if you do not have a vestige bound, or if you do not currently have access to its abilities.

Supernatural blast is usable a number of times per day equal to 1/2 your eldritch pactmaster level, rounded down (e.g. 1/day at 2nd level, 2/day at 4th, 3/day at 6th, etc).

Vestigial Awareness (Su): Beginning at 3rd level, you can convince your bound vestige to focus on alerting you to danger rather that reveling completely in the sensations that it perceives through your pact. Whenever you make a good pact with a vestige, you gain a +2 bonus on initiative checks for the duration of the pact.

Pact Augmentation (Su): At 5th level, you may select one additional ability from the list of pact augmentation abilities available to binders (ToM, p. 11). At 10th level, you may select two additional abilities. These abilities stack with any you receive from your other binder levels.

Vestigial Resilience (Su): At 10th level, you can will a bound vestige to focus all its supernatural energy on replenishing your wounds. Once per day, as a free action, you can enter a state that lasts for 2 minutes. While in this state you give up all powers and abilities granted by that vestige, but gain fast healing equal to the vestige's level/3, rounded up (e.g. a 2nd-level vestige grants fast healing 1, a 4th level vestige grants fast healing 2, and a 9th-level vestige grants fast healing 3). This ability stacks with any fast healing you may already have from other sources (including fiendish resilience).