No I don't think ETHD is related to ETH in anyway, there's definitely no involvement of Vitalik.
I think the price action is hype and people wanting to get in on the profits. It is a airdropped coin and that also means that it relies heavily on its community to make it work.
If its being mass dumped then I can't really see a future for this.. or I have a thing or two to learn still.
ETHD seems to also have no plans of being a blockchain platform for DApps. It will however will implement smart contracts as a priority feature.
I won't touch the coin atleast. Imo the name is a bit traitorous. I don't know anything about the dev aswell.. or how serious the community behind it is.
You can check it out yourself here:
https://www.ethereumdark.net/