A slightly more fun way to disable Windows Defender (through the WSC API).
With a little bit of reverse engineering, I turned this service into a service that could add my own stuff there.
Limitations
Sadly, to keep this WSC stuff even after the reboot, no-defender adds itself (not really itself but rather Avast's module) to the autorun. Thus, you would need to keep the no-defender binaries on your disk.
no-defender latest version is v1.0.1 (changes and downloads at https://github.com/es3n1n/no-defender/releases).