I propose the current parts of the Hero/Minion versions, being
Automatic-attacks (2):
Balrog (1st attack) -- 2 strikes with 16 prowess
(2nd attack) [...]
Special:
[Hero:] If Balrog of Moria is in play or if Durin's Bane has been defeated, the first automatic attack is canceled.
[Minion:] If a manifestation of Balrog of Moria is in play or defeated, the first automatic attack is canceled
be replaced by
Automatic-attacks (2):
(1st attack) If a manifestation of Balrog of Moria is not in play or defeated: Balrog -- 2 strikes with 16 prowess
(2nd attack) [...]
Special: ...
Reason: As I understand, if BoM is in play, the first AA does still exist, technically. One could argue that, e. g., Tidings of Bold spies could trigger a Balrog attack, as Tobs doubles the attack but not the cancelling effect.