Impetuous Sunchaser - If we're going for Icarus, then it feels like some sort of self-triggering sacrifice effect would have made more sense than a "must attack" effect.

Hits
Nyxborn Eidolon: There's just so many ways of interpreting this soul's story, all of them hopelessly tragic.

Kiora, the Crashing Wave - Very different art style but I kind of like it.

It's a japanese reference so...

Whelming Wave - I do like it, although I'm a little surprised that it hits merfolk and fish.

Archetype of Aggression - This card feels like a green guy who accidentally color-shifted into red. I know that trample isn't outside the red pie, but I certainly would not have picked it for a red "archetype," of all things.

Actually, it's impossible to explain in any but one way.
It is a created soul that the gods chose to make in the form of an Eidolon.

And I am not going to start in again on moral objectivism. It's a losing battle, but you all know where I stand.
Ashiok's mind ripper would turn around and do the same to the population, not just somehow stay with evil creatures.

Considering the Pseudamma thing, I think one would also imply it belonged to a living person and somehow ended up remade into a nyxborn. Alas, always tragic, with or without a genuine body.

Floodtide Serpent: I like the implication that, should Thassa get tired of Kiora's shenanigans, Kiora can throw enough serpents at Thassa's faithful, weakening Thassa to the point that the blue god can't do much of anything to the planeswalker.