Iris will need a new daddy and the MC can step up.
I can see Melissa adopting her and forming an actual family.
Of course
Iris herself can take the hit in something meant for John.
John death would be the worst, it would drive a wedge between mc and iris as well as mc and Erryn probs mc and Mellissa too. Probs means john is a dead man walking
Iris heard Erynn explaining what Ethan was doing and made no effort to dissuade him from helping. John was asked his opinion and insisted on helping, so her holding MC responsible would make no sense.
Also, nobody would expect it escalating from blackmail to murder.
I wouldn't blame Iris for putting the blame on MC-Erynn if something like that comes to pass.
She would be so hurt at losing her only family i can understand her lashing out, even if John chose to enter this of his own volition.
But she will come down since those people will be her new family.
Erynn and Melissa would be saddened but i don't see this driving a wedge between them and MC, maybe Erynn will have one of those "i need to get away from everybody" if Ethan is still at large, but they are always short lived.
I hope it isn't John or Iris, i hope they get a nice family ending.
If someone gets in a coma for a while would do the trick, have us in pain but not permanent.