A state of being that combines psychosis, rage, the ancient arts of the samurai, and sword skills learned on Youtube. Often found present in players of online, text-based roleplaying games.
Alternatively used as a verb: to go full bushido, meaning to completely lose your shit and go crazy, again often involving sword skills learned on Youtube.
"Man, that guy went full bushido on that mob." or "That guy is seriously full bushido."