[This post was written on May the Fourth (be with you).]
So I had testdisk running on my server’s disk all night long.
It found two partitions. The boot partition that I had already gotten by using parted’s rescue mode and another really small partition that I’m not sure was there. Maybe it allocated data from the end of the disk that hadn’t been partitioned and made a partition out of it? Maybe it can’t recognize an encrypted LVM? It’s probably the latter. I’ll try booting from it (since now I have Grub again) but I don’t have any hopes, really.
2 hours later
It’s not booting. Not that I expected it to boot. After all, the LVM is toast. But it would have been a nice, magical solution. Now I have to set up the server again, and connect it with Perfect Dark again. Goshdarnit.