Q: I sold an iwatch, i unsynced from the iphone and from icloud page, but its still blocked for the new user what else can i do?

They cannot use either the Apple Watch or iPhone since it's associated with your Apple ID and they can't change it without your password.

Doesn't matter. He can't change the Apple ID password on the Apple Watch without your password.

Honorable thing to do would be to offer a refund and have him send the devices back to you.

You should have unpaired the Apple Watch prior to the sale > What to do before selling or giving away your iPhone, iPad, or iPod touch - Apple Support