Basically, the idea is, when a character accumulates enough ki, his aura becomes a permanent effect, like Ultra Instinct or kaioken.

How this could work is, once a character hits a certain threshold while charging ki, the aura doesn't dissipate when he stops. The aura could disappear if the character ki drops to 0 or if he's knocked out by a dash attack. Some characters could have permanent aura by default, like kaioken Goku.

de echo,me gusta esa idea pero que tal si el personaje emite pequeños rayos a traves de su cuerpo,cuando el ki limitado este lleno y desaparesca cuando las barras de ki no esten del todo completas