Regine will sneak around behind the shaman and attack him, being an Unaware opponent.
She's also dropping her Pass for Human bloodgift, meaning she currently causes Fear - that means anyone present who does not cause fear themselves or have immunity, have to succeed at a Willpower roll in order to do anything, otherwise they stand there trembling in fright. (they can't attack, dodge, parry, charge, nothing, until they pass a willpower save)
Attack 1: (1d100)[54] vs TN 96 (66 base + 30 Unaware opponent)
Damage: (1D10+6)[8]
If Fury: (1d100)[6] vs TN 96, (1D10)[2]
Attack 2: (1d100)[77] vs TN 96 (66 base + 30 Unaware opponent)
Damage: (1D10+6)[13]
If Fury: (1d100)[64] vs TN 96, (1D10)[7]
Attack 3: (1d100)[90] vs TN 96 (66 base + 30 Unaware opponent)
Damage: (1D10+6)[13]
If Fury: (1d100)[68] vs TN 96, (1D10)[3]
Assuming nothing improper, 8, 13 and 13 damage from behind to the shaman.