Targeting Joanna IF the rest of the party's attacks were enough to disperse the mob. If the mob was not dispersed after all of the other attacks, then target them first.
+8 to hit vs. the mob (Imos) if hitting them instead of Joanna. +8 damage vs. mob if same (or if Joanna is Undead)
Attack 1
Rolled 1d20+18 : 11 + 18, total 29
Attack 2
Rolled 1d20+13 : 19 + 13, total 32
Damage 1
Rolled 3d6+6 : 2, 4, 1 + 6, total 13
Damage 2
Rolled 3d6+6 : 6, 4, 1 + 6, total 17
Hasted Attack
Rolled 1d20+17 : 13 + 17, total 30
Damage
Rolled 1d4+6 : 1 + 6, total 7
Assuming the ability for the Soul Spear to dispel any defensive spells on a target I hit with it is passively activated on hit, otherwise ignore
Dispel Check 1 (From first attack vs. Joanna)
Rolled 1d20+12 : 12 + 12, total 24
Dispel Check 2 (From second attack vs. Joanna)
Rolled 1d20+12 : 18 + 12, total 30