Concept AU where Kronos is able to charge his powers, only now in a smaller size due to not being completely back to normal, escapes and takes Hades' place by pretending to be him not even needing shapeshift since they are so similar.
They obviously fight, and Kronos tries to absorb Aidoneus' strength, but since he hasn't used his powers in so long, ends up also de aging our boy into his 8th year old self, when he was 3 years into his prison. But some of his memories remain, just like his scars, that go back to bleeding.
Hecate saves him and runs, but Kronos manages to strike her. She makes it to the mortal realm and Demeter's space just before her time goes out and she passes out very close to hybernation.
When 8 year old Aidoneus wakes up and sees himself in the arms of what he deems a dead body with his father nowhere to be seen, starts to run in desperation and cry for his mama. Cue a very young Kore, Krokos and Withy walking by the gardens and seeing a half dead blue boy calling out for his mama.
I could make a part 2 if this proves to be a good idea. Or get my ass moving and actually write it.