The Alchemy Leviathan delivers near active pickup style gain handling, a huge sound, but with traditional passive design.
It's wound with extremely thin 46AWG wire with extremely high resistance, to provide extremely extreme output!  Outputting in excess of 35k in the bridge, and around 28k in the neck, these pickups require intense string pull to retain note definition, clarity, and attack. This is achieved by loading each pickup with three magnets - a ceramic mag in the bridge, and an AlNiCo V in the neck, each flanked by two ceramic spacers. This high string pull gives really tight bass response, and (paired with the extreme output) incredible ability to cut through stacks of gain at any volume, making it the perfect passive set to use for extreme metal, heavy drop tunings, and anything where tons of gain and distortion is required.
The bridge has a crushing rhythm and searing lead tone, capable of handling anything you can throw at it, where the neck has a slightly smoother treble response, for really full, thick leads, while still having easily enough string pull to separate and define notes in fast runs. This allows you to have active-like handling of extreme gain without the need to modify a guitar with battery packs etc.
However, the main advantage of the Leviathan over the active pickup competition is its ability to deliver organic, lush clean tones. Due to its traditional passive contruction, the Leviathan pickup set offers a genuinely organic and true humbucker sounding clean tone, albeit warmer and more compressed than that you'd get from a lower output or PAF style set. This allows the Leviathan to excel in playing modern progressive metal, death metal, and djent; where lush, warm cleans, searing, defined leads and hyper aggressive, distorted chugs are often required in tandem.
 
The Leviathan really offers massive sound, with massive potential.
 
Note - The Alchemy Leviathan is more expensive to manufacture, due to its use of multiple magnets in each pickup and more costly and delicate winding wire