Developer Jeremy Rand wrote in to report his functioning port of Whonix 16 to OpenPOWER. (I should point out that all links in this article are "clearnet.") Whonix is a second operating system based on Kicksecure (a Debian derivative formerly known as "Hardened Debian") that runs within VMs on your existing OS (compare with Tails). All connections within it are forced through Tor, using different paths for different applications; additionally, it useskloak
for keystroke anonymization and secure network time synchronization instead of NTP, has higher quality RNGs, and enables AppArmor and hardened kernel profiles to prevent against other types of attacks.
The current release of Whonix is based on Debian bullseye and runs "native" on OpenPOWER KVM-HV using libvirt. Note that ppc64le isn't a top-tier architecture yet, so there are roadbumps: due to a bug in kernel versions prior to 5.14, currently you have to use Debian experimental for the VM, and there may be other glitches temporarily until support is mainstreamed. But if you bought an OpenPOWER workstation for its auditability and transparency, I doubt something like that's going to trip you up much. Detailed installation instructions, including Onion links if you prefer, are on the Raptor wiki.