[Nicol Bolas]

Some thoughts after testing out most of these items. (Any and all players can go to our test server to try these out for yourselves. Be warned, some are not balanced):
Clairvoyancy: A neat detective item honestly. Watch the video in the workshop link if you cannot test it yourself. Doesn't seem to broken or overpowered. In fact, having it might be a drawback at times because you could get a vision in the middle of a fight.
Barnacle: Honestly unsure about this. It's a good traitor item and does its job as a trap fairly well, however there are some drawbacks. A major one being it's not visible to other traitors. This means you'd have to warn about placing it, and that's a whole mess of rule complications. 
Blink: While being able to teleport around seems overpowered, it comes with drawbacks. Firstly, it's very obvious you're using it. Second, you can't spam it, as you'll wear the charge out and be stuck with an item that does nothing. Also a cool side note: If you manage to teleport on top of someone, it goombastomps and instakills. Apparently it's an intended feature, Neat. (Harder to pull off than you think)
Handcuffs: Another item I'm unsure of. While a useful tool for detectives when used right, it could very often be used by trolls. Also, if it falls into a traitor's hands, it's a powerful tool in their arsenal.