22? I was almost 30, and it was still an incredibly difficult fight. Get rons of revive bottles, 50 should be more than enough, and 99 med liquids. Ryfia's song is a great move: spam it.

Do you mean fafnir?the dragon that dynos revived?if so....then here is what you can do..:
1.it is weak to light attacks(light magic) example:banishing ray
2.spread your party out,it has this rigil area attack,so,if you are low level,you might want to avoid this attack
3.spam light magic and put ryfia as the healer.just heal,defend and spam light magic and you should be fine...

If this does not work,then just level up more...