Why has the price dropped like a stone? I mean 21 sat wtf

This is weird. Difficulty goes up and price goes down? There are some shenanigans going on I'm telling you.
Maybe someone was dumping once again. It's climbing up back now.
Is FCN currency somehow connected with BTC?
As a cryptocurrency, FCN is fork of Bytecoin. The BTC system is very different in terms of software, and it's not anonymous (it's pseudo-anonymous). FCN is as anonymous as it gets.
However, all cryptocurrencies (CCs) are related to BTC in the way that all fiat currencies are related to the US Dollar. Almost all fiat currency exchanges base their rates on the US Dollar, and in the CC world, CC exchanges base their rates on BTC.