After watching the fights this weekend, I was reading about some of the fighters. In an interview Mousasi talked about how he preferred to not have a nickname and that he doesn't really care for being called "The Dreamcatcher". He then went on to state that he has a lot of nicknames, one of which is Kengo in Japan. I didn't recognize the word. When I put the symbols into the translator it came out as "fist, Australia". That didn't make any sense so curiosity got the better of me and I decided to figure it out.
The translator told me that 拳 meant fist and that 豪 meant Australia
So I jumped over to Mousasi's Japanese wikipedia page and found some answers. It stated that many Japanese fans noted that Mousasi was strong on the feet and on the ground. In a sense he fought with two weapons, his stand-up and his ground.
One of the most famous samurai of all time was Miyamoto Musashi. Musashi, which sounds a lot like Mousasi, was famous for fighting and winning over 60 duels (often to the death) and for fighting with two swords. So not only do they have similar sounding names but they both fought with two weapons.
In Japanese you could say that Miyamoto Musashi was a Kengo 剣豪.
剣豪 means master fencer
剣 means sword
So the sound is the same "kengo" but the symbol for sword has been replaced with fist.
It is interesting to see how this nickname came together and I for one, like it better than The Dreamcatcher.