Keep in mind that Happousai already has some rather impressive,
albeit strange, attacks...such as the so-called "Bean Jam Blowout"
whirlwind, or the massive battle-aura attack he frequently
uses...granted, that one's more intimidation than anything...
As a matter of fact, this battle aura (and its paralysis it induces) is
a representation of the legendary effects that true masters are said to
be able to achieve. It is a Ki attack in every sense of the term. (and a
mighty one. Ranma can get up, although shakily, after taking a perfect
ShiShi Hokodan, But, since Happosai fighting spirit is higher than his,
he has no chance to free himself from Happosai's hold, except if this
one is distracted. Beside, you can't dodge such an attack...)