To open an encrypted luks partition
sudo cryptsetup open /dev/sdXX [label]
To mount this opened luks partition
sudo mount /dev/mapper/[label] [mount-point]
The label can be anything your want, like home, or whatever.
Running in chroot, ignoring request: list-units
Systemctl doesn't work in chroot, many service specific systemd commands don't work within chroot.
Only real option on systemd distros like Arch and Manjaro is systemd-nspawn, but in this case it is not necessary as the error message has been captured.
FWIW I don't think the issue is with your system, but actually a systemd 241 regression.