Merestil's right. Due to the dependency, in layer 4 Enchanted Evening will go first regardless of timestamp, making Dark Confidant's type "Enchantment Creature -- Human Wizard". Then, still in layer 4, Opalescence will start to apply as well since Confidant's an enchantment now (though it doesn't have much practical effect since Dark Confidant will still end up an "Enchantment Creature -- Human Wizard"). Then up in 7b Opalescence will make Dark Confidant 2/2.
I have all three out. Is the Confidant a 2/2, or a 2/1?
Dark Confidant
1-
2-
3-
4- Enchanted Evening. Now it's an enchantment.
5-
6-
7a-
7b-
7c-
7d- Opalescence. Now it's 2/2.
7e-
So it's a 2/2.
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Lightning Bolts don't kill creatures. State-based actions kill creatures.