Four modulated “phase shifters” in series plus a number of tweaks to offer more sound variety.
The video is in mono but the effect is in stereo.
Update V2: Stepped mode.
In additional to the conventional phaser effect, you can now crossfade seamlessly between a classic phaser and a stepped version, all in one AUv3 effect thanks to Drambo.
Two separate LFOs for independent speed control.
I like it.