One potential ending I've thought about for the dad!Ethan au is very involved with the Carlos side of the plot. Carlos clashes with Ethan a lot after the demigod thing comes out and Carlos is furious at Ethan for keeping it from them and threatens to join Alabaster's organisation which really frustrates Ethan because he has spent this whole time trying to prevent the kids from experiencing what he did and now Carlos wants to charge head-first into that life. They have their first proper fight and Ethan stresses all the nights he spent washing his friends' and family's blood off his hands and asking Carlos if that's really the life he wants to live but tensions are high and they're not mincing their words.
Anyway, fast forward and Alabaster has Ethan under him and smugly asks if Ethan has any last requests. Ethan doesn't feel like playing this game and just asks Alabaster to make sure the kids don't see him like this (read: find his body) because he wants to spare them from that trauma. Alabaster hates Ethan and he doesn't agree with how he's sheltering the kids, but he also understands him and he knows how important this is to Ethan so he gives Ethan his word. With that assurance, Al goes to kill Ethan and Ethan kneels like a supplicant. That's all fine and dandy until Carlos bursts in to save his dad, at which point Ethan tries to defend himself and Al tries to stop his attack but by then it's too late. Ethan gets stabbed and Carlos tries his best to stop the bleeding while Ethan and Al are both trying to get him to close his eyes or turn away but he can't let go. The angsty version of this ending is Ethan dying in Carlos' arms and Carlos and Al feel very guilty about it because this kind of death literally could not be any closer to how Ethan absolutely did not want to die. He spends the entire au talking about how he doesn't want his kids to have the trauma he is forced to live with and makes sure they never see him like this only to die a bloody death in his kid's arms. Later in the night Carlos is standing over the bathroom sink looking at his hands which are just covered in Ethan's blood and all he can think of is that argument he had with Ethan and how this is the last thing Ethan wanted for him, and Carlos realises Ethan had a very good point about that whole "you don't want to spend your life watching your loved one's blood pour down the drain" thing.
The other option is Alabaster gave Ethan his word that the kids wouldn't see his dead body and while mama did raise a fucking dumbass, she didn't raise no quitter! He more or less shoves Carlos aside and puts his whole Alabussy into making sure Ethan Does Not Die and unlike most things in Al's life, he does a very successful job. Ethan still has a lot of slow and painful recovery to get fully back on his feet but it provides a great opportunity for him and Alabaster to reconcile as Al slowly nurses him back to health with the help of the kids, which turns out to be a great bonding experience. So basically Carlos accidentally reverses his dad's divorce by walking in on their attempted execution.
