@Physical abilities;
The Black Court are very, very strong. But they aren't fast. Limit most of them to inhuman speed. That way they don't totally outclass mortals in dodging attacks and being able to keep the distance open. Also, if the catch is the same, don't give someone both Mythic Toughness and Physical Immunity - it doesn't make sense and just takes up points.
@skills:
Highest skills (at Epic) should be conviction and endurance. BC elders are millennia old and both ridiculously tough and very powerful mentally. Beyond fitting their age, having the passive skills as highest gives you extra consequences without needing to spend refresh on them and also fixes their problems if them being too skilled in active skills such as athletics or fists and thus totally outclass mortals.
@Shapeshifter;
You've given those guys more points than there are abilities to take. Since they already have mythic toughness and strength and inhuman speed, and many creature features to boot, giving them more than 10 modular points is self-defeating; they really don't have anything else to take. Add another 3 points for True Shapeshifting (cause the base template already has beast form). Then a stunt to reduce the supplemental action penalties from shifting form by 2, and a -2 power so that any form-changing that takes a full action now takes only a supplemental action. That's 18 points so far. Then add Ritual: Transformation and Disruption and you're done at a total of -47 refresh. They can practically take any form within moments (even change more than once per exchange) and they can be very powerful combatants if they upgrade their toughness to immunity and their speed to mythic with modulars. They also got powerful, if slow, magic; ritual may not seem much but once they reconfigure their points to mythic recovery they can start casting rituals at over 25 shifts easily.
@Spellcaster;
A mere 16 refresh put entirely into spellcasting powers gets you at least 16-shift evocations if you're a blaster. Then give them those powers from the custom powers thread to increase their mental stress track by, say, 3 for -3 refresh. And finally, give them Supernatural Recovery to cover ritual blood sorcery and you are pretty much done. Given the set of Evocation, Stygian Necromancy (as per KN, replaces Thaum for vamps), refinement 9, The Sight, and putting it all into Evocation allows you to do some really nifty stuff with "Thaumaturgy at the Speed of Evocation". For bigger rituals, the Black Court elder not only can fuel magic with his consequences - but can recover consequences with free recovery periods each time he uses his bare hands to sacrifice someone due to "taste of death". Which can amount to some really scary, really big magic, really fast.
Mindbender;
Start with giving Ritual: Psychomancy (-2). Once you take out a mortal with, say, domination, he's already taken out. Rearranging his mind to, say, make a Renfield is a trivial task you can do with a ritual at your base Psychomancy complexity (around 7) that can be done in a couple of exchages (or maybe only one) because you're going to have a discipline of around 7 as well. And said ritual will allow you to do a lot more things other than making renfields.
Incite Obedience, At Range, Lasting, Potent (-4) to use domination in combat. Once they are taken out, the BC elder can immediately use actual Domination in his next action to get a more permanent and more finely-tuned control.
Senses (-3) for full telepathy with all his thralls regardless of distance or interference. He can command them telepathically after making a Psychomancy ritual on them to establish a permanent mindlink - Harry Dresden did that with Elaine and it lasted for decades. A vampire with a lot greater ability in mind magic could do it casually, so no need to spend extra refresh to send commands; the telepathy sense is there so he knows what's happening, not for communication.
Greater Glamours (-4), if you want.
Improved Mindreach (-1) giving mental powers a +2 range.
Field of Dead Eyes (-6) allowing him to affect 3 zones with mental powers without penalties. For every additional zone, -1 to his roll. (that's the correct pricing; a zone is 2 shifts price-wise)
Quintessential Vampire:
No Salvation (-3) : only the vampire's actual catch can bypass their toughness, not powers that can satisfy catches in general or magic that imitates it.
Physical Immunity (-4), the catch being that all attacks bypass it but deal only half stress. Essentially a half-immunity that makes them that much tougher without making them invulnerable.
Supernatural Recovery (-4)
Supernatural Speed upgrade (-2)
Ritual: Elementalism (-2). Coupled with Mythic Recovery, allows some fairly interesting stuff. Remember that following conjuration rules, the difficulty to cover an entire park with "rain of frogs" is merely 6. Covering a city could probably be done with a 20. So you don't actually need a new, specific power to conjure weather - and ritual can do a lot more than just weather.
Entropic Claws (-1) is good. However Curse Transmittance has no rules basis - you need to base it on some other ability to price it correctly. Therefore;
Blood Curse (-3). You can curse a person's blood, changing its nature and causing horrible spiritual torture. You can do attacks, maneuvers and blocks at Skill+2 and weapon 4. Being taken out by the Blood Curse makes the victim into a lesser creature of the night under your command. Based off incite emotion - then add the following;
Blood Mastery (-3). There is no limit to the number of times you can feed off blood with Blood-Drinker. In addition, you can combine a physical feeding with a lethal Blood Curse.
Telekinetic Reach (-2). A quintessential vampire has a physical reach of 3 zones, as if she were a much larger creature. She is not actually bigger though; the reach is due to telekinetic power. That would allow such a vampire to rip apart enemies from afar, or reach out to the top of a building to drag herself up -seemingly flying- or lift and throw massive objects and perform other physical actions.
Grace of Darkness (-4). A quintessential vampire is not only fast; she has the coodrination and mental speed to performs multiple similar tasks at once. Provided she can reach them, she could attack or physically manipulate targets in up to two entire zones at once without penalties. She could affect more zones at a cumulative -1 penalty per zone to her action.