Webkokushibo is the demon with the most blood demon art techniques at eleven describe forms, though it is suggested that he knows at least sixteen.
Akaza comes next with ten,.
Webakaza possesses a range of powerful blood demon art techniques, showcasing his superhuman abilities in battle.
Webwiki labels his technique development as a use of his bda, so ‘destructive death’ annihilation/air/disorder are considered his actual blood demon art, destructive death.
Webboth are his blood demon techniques called hakai satsu or destructive death, though yes the compass needle is the secret behind akaza, and it the most powerful defense.