http://finalfantasy.wikia.com/wiki/Devout
Tornado as white magic. Stop your retarded crusade please mr. mage.
Anyway it'd be cool if Tornado was a high level conjurer spell if/when the level cap is raised. It could be a cool crowd control/damage hybrid possibly like Estellios suggested. Of course there's still Aeroga/Stonega but the blizzard spell skipped a line so why not this one? WHMs already do a lot of nuking in parties if things are going well so it'd be cool to see them get some growth in that department.
edit: or, hell, why not a Devout job? Tornado, Aeroga, Stonega, Quake, Reflect. Go!