"He closed his eyes and tried to feel for all the distributaries bifurcating from the vast, central torrent of Blaze Energy."
A kanaala can control the Blazes within a wielder, or he can manipulate existing Blaze Energy forms. He also has the ability to permanently quench a wielder of her power.
Kanaala are the only men who can safely sleep with wielders, though this is dependent upon their grading. They are born with their full potential already reached, and do not mature into their abilities as wielders do.
Prospective parents fear giving birth to kanaala, since the child's arrival will almost always result in the mother's death. The same is not true of wielders unless the child has the potential to be especially powerful. It is thought that this difference has something to do with the child's latent Blaze abilities at birth, which is at full potential in kanaala but not in wielders.