Master of Chaos!
However its Pokédex entries state that it shows off its muscles but according to its Sun entry, it is unknown if it is a boast or if it is indeed a threat. So that means it may not even be a communication method but it is shown that Ash and Kiawe have bonded with the Buzzwole.
True, but there are three things known about Buzzwole that is a given. Like a mosquito, it less eats things and more drink things. (Like Snorlax!) Its power can pulverize a large truck and as a fighting type... it translates to it getting into a fight with others. The last one is the flexing, why does it flex?
It's an unpopular opinion of mine. (I got a lot of them!) But I like how the anime portrays the UB's in comparison to how everyone views them as. (Scared animal in an alien world, a creature that's mind set is so different that it may not even be aware of the destructive power it can cause. Blacephalon's case it is doing what the data would say it would do in startling people for energy. In comparison to generic aliens that want to destroy everything for potato reasons.)
Nihilego being the only one that is accurate as a 100% threat due to how it is a creature of instinct and only instinct! In addition to it's venom that can really mess your head up. At least the other UB's have a mindset that can be understood, Nihilego has none!