Clarifying some basic concepts of Mass Murder & Orks , please help me!

I was wondering what's the outcome of this situation:
An Ork, possessing just the Insubstantial Trait & a Weapon Trait, is attacking several ven, none of them packing magickal weapons (so they cannot damage the Ork if it becomes Insubstantial, per the rules).
The ven's side Leader wins Priviledge, & has the option for first wager.The player chooses to give a Rank 5 Injury to the Ork.
a)The Ork is dead, dead, dead, period. No chance of retaliation!
b)The Ork uses its' Wager next, to become Insubstantial, thus evading the Injury (but not being able to deal any damage, as per this Trait's rules).
Thanks!
V