[Inconspicuous Kitty]

The center tile of Setting Sun is dense. Since the ability is up in the air, I doubt this is intention.

[Autumn]

It also counts as a wall for skills like dense thunder and on the ropes.

[Snake]

That also makes a funny interaction.

When you're at the center of an enemy's Setting Sun, and use Setting Sun, the enemy's Setting Sun disappears, and yours take place.

[Neus]

This has been corrected.

As for Snake's issue, this is just how field objects work. They will typically replace the same type of object in the tile. Setting Sun can probably be destroyed with Magaisendo too, for that matter.

[Snake]

I mean, it's not really an issue. It makes it possible to play hot potato with Setting Suns. And yes, Magaisendo and Pillawag can get rid of Setting Sun, confirmed.