Dos amaterasu has more forms?

She does have some Karmic Transformers, that you get after completing the game, but you have to have done various things to get them, I can't remember the exact number of how many there are.

if your talking about wepon wise, she has 15 in all.
wepons:
Mirrors:
Divine Retribution (1)
Snarling Beast (2)
Infinity Judge (3)
Trinity Mirror (4)
Solar Flare (5)
Beads:
Devout Beads (1)
Life Beads (2)
Exorcism Beads (3)
Resurrection Beads (4)
Tundra Beads (5)
Glaives:
Tsumugari (1)
Seven Strike (2)
Blade of Kusanagi (3)
Eighth Wonder (4)
Thunder Edge (5)