A while ago, when playing through FFIX, I decided to level up all the characters and have as many of them learn as many of their abilities as possible. Switching Vivi out, temporarily, I replaced him with (delete as appropriate) Dagger/Garnet.
I found that summoning Shiva (since I was fighting those dragons) was effectively just as good as casting Blizzaga; I was doing similar damage and spending a similar amount of MP to call her. In fights against considerably weaker enemies, I also found that Dagger/Garnethad fairly decent physical attack power, though admittedly not on par with Zidane, Steiner or even Freya. She also gets all the mandatory healing spells, namely the Cure series, Life and some rudimentary status cures, but unlike Eiko she didn't have access to the really big guns like Full-Life, Esuna, Dispel or Holy.
So add her half-decent physical prowess and her excellent summoning power to this (so totally nothing like Black Magic in the way it does magic based elemental damage that also can't be reflected, no sir) and in all seriousness, Dagger/Garnethas all the makings of a Red Mage. Now I don't feel so jealous of all those "Male Red Mage" and "Female Red Mage" NPCs I kept encountering :)
Just to give a little rundown of where I'm coming from with "Black Magic"...
Shiva = Blizzaga
Ifrit = Firaga
Ramuh = Thundaga*
Atomos = Demi
Leviathan = Water (remember Water was sort of a higher powered spell in this game as well)
Odin = Death
Bahamut = Meteor, but now it never misses
Ark = Doomsday, but without killing ur d00ds
What do you all think?
*Uh oh , another game where I think there's a superior alternative to a Black Mage. When will this madness end?