I nominate Camerupt for C tier.
With a similar specially defensive set to the one in the already existing NU analysis (just earthquake over earth power, and a sassy nature), Camerupt can easily switch into every offensive electric type with ease and set up rocks, toxic/phase, or try to deal damage or get a burn with its STAB moves. And unlike Swampert and Rhyperior, Camerupt doesn't have to be wary of random grass coverage, so it's especially a good check to Raikou and Chandelure. It can also check offensive fire types pretty well and retaliate with a powerful STAB earthquake, but with a lack of reliable recovery and only average bulk it doesn't like taking repeated flare blitzes, V-creates, and fire blasts.
Camerupt's only weaknesses are ground and water, and on top of that it has solid rock to help takes those hits better. But unfortunately Camerupt is never going to take any water hits well at all, nor physical ground type attacks. Solid rock does come in handy for switching into Shaymin's earth power, however. Camerupt's main advantage over Swampert or Rhyperior is its typing; it has the key resists of a fire and ground type without being weak to rocks or standard coverage moves. Its ability to spread burns with lava plume is also a bonus (although Swampert pretty much does the same thing with scald).
I chose Camerupt for my team mostly because it finished off the FWG core on my team and it could set up rocks. I also needed something to deal with sub CM Raikou, and Camerupt does the job perfectly. It's mostly outdone by Swampert and Rhyperior in terms of bulk and offenses, but it has a niche and is totally viable in UU. I'm just surprised no one has ever mentioned it here before, and that it wasn't even used 400 times last month in UU. I hope more people will try it out once they read this.