All of the drums are made in Serum and layered with organic drum loops to fill out the groove.
A rim shot made on Serum is layered on top of the snare to distort the phase, making the final snare sound more organic.
The bass is made from old school reece sounds, sliding out of phase. Mefjus creates these with two layers of the same reece; each oscillator is slightly detuned by 2 - 4 semitones. All made in Serum.
Some of the bass sounds come from a Virus TI synthesiser.
The bass is split into 'Reece', 'Stabs' and 'Groove' groups. The combination of all three is what makes up the bass sounds and keeps things interesting.
UAD Studer A800 & iZotope Trash plugins for harmonic distortion on the bass.
Certain UAD plugins will clip internally if you run the signal loud into the plugin. Clipping shouldn't always be avoided; it's a creative tool that you can use to create harmonics.
Mefjus has 19 send effect channels, applying various FX's throughout the track for variation. He likes to keep the main sound pure, but add reverbs on send FX's to avoid altering the phase of the original sound. MV: Seems like this is a large part of his workflow (using send FX's to apply creative processing).