one of the Fchannel0 forks is still getting updated, and has an instance running.

link to instance, but visit only if you are completely degenerate

https://usagi.reisen/

But it seems to be an isolated instance, as the federation appears to have been broken:
github.com/anomalous69/FChannel/issues/9
usagi.reisen/followers

more info:
fediverse.wiki/wiki/FChan