Methuselahs in Trinity Blood have a standard strength, such as: retractable claws that are as strong as steel, ten times faster/stronger than Terrans/humans, rapid regeneration as long the heart isn't destroyed or they aren't poisoned by silver, etc. The ability to "haste" even beyond their limits, inability to age after their Awakening, etc. However, they have sub-races with rare special abilities among them. I'm going to list what I remember on top off my head:
Basilisk: The ability of poisoning and petrifaction of their targets.
Doppelgänger: The ability to shapeshift (by changing the order of the cells in their bodies' surfaces) and create a disguise.
Dryad: The ability to control plant life and (apparently) joint with vegetation (??).
Fairy: The ability to fly with high speed by emitting air from the support-lungs in their backs. Additional subsonic waves emitted as weapon during their flight.
Ifrit: The ability to produce flames about many times stronger than a napalm bomb.
Medusa: The ability to grow your hair and strengthen it as a weapon.
Mermaid: The ability to produce a hypnotic song that lulls people into sleep, ability to shapeshift into a half-shark in contact with water.
Nachzehrer: The ability to melt/evaporate stuff with their shadow? (I'm unsure).