How many demon forms does Mirajane have? As what I've known, Mirajane has only 3 forms :


Satan Soul
Halphas
Sitri


I wonder if how many demon forms does Mirajane have (not yet discovered)? Is it three forms only?
According to  Mashima, says that there are 72 demon forms of Mirajane, but It was not yet revealed in manga and anime,

Mashima has went an interesting way with Mira's powers. 
Though if you know about demons from the Goetia list or other animes you probably already sort of know.

Lisanna has things like Animal Soul: Rabbit, Animal Soul: Tigress 
Elfman has Beast Soul: Weretiger, Beast Soul: Lizardman

Animals and Beasts. 
Though in Mira's case of course she'll have demons for her forms, and Mashima has decided to get them from the Ars Goetia list. 
So it'd look like for her, Satan Soul: Sitri, Satan Soul: Eligos etc.

Here's the list of demons:


King Baal (bael)
Duke Agares
Prince Vassago
Marquis Samigina
President Barbas
Duke Valefor
Marquis Amon
Duke Barbatos
King Paimon
President Buer
Duke Gusion
Prince Sitri-Shown
King Beleth
Marquis Leraje
Duke Eligos
Duke Zepar
Count/President Botis
Duke Bathin
Duke Sallos
King Purson
Count/President Marax
Count/Prince Ipos
Duke Aim
Marquis Naberius
Count/President Glasya-Labolas
Duke Buné
Marquis/Count Ronové
Duke Berith
Duke Astaroth
Marquis Forneus
President Foras
King Asmodeus
Prince/President Gäap
Count Furfur
Marquis Marchosias
Prince Stolas
Marquis Phenex
Count Halphas
President Malphas
Count Räum
Duke Focalor
Duke Vepar
Marquis Sabnock
Marquis Shax
King/Count Viné
Count Bifrons
Duke Vual
President Häagenti


72 Demons

link to list: http://en.wikipedia.org/wiki/List_of_demons_in_the_Ars_Goetia#Prince_Sitri