What happens if a Cube of Force intersects with creatures?

Question

The cube of force states that

a barrier of invisible force springs into existence, forming a cube 15 feet on a side.

And the effect of the 5th face says:

Nothing can pass through the barrier. Walls, floors, and ceilings can pass through at your discretion.

How would this work if there was a Huge (or larger) living creature currently occupying the space that the wall acts? Would it cut the creature in two, freeze it in space as it can't move in any direction, or force it to be on one side of the wall?

So, for instance if there was a 26-foot-tall storm giant, and I stood next to it and activated this 5th face, what would happen to the giant?

Answer 1

Nothing special happens; most likely, the giant simply can't move

And neither can you, actually:

If your movement causes the barrier to come into contact with a solid object that can't pass through the cube, you can't move any closer to that object as long as the barrier remains.

The cube doesn't mention what happens if it spawns into existence with somebody already there, but the most logical assumption would be that the creature now simply can't move because it can't pass through the barrier. But you can't move either, because you can't cause the giant to move through the barrier.

How exactly this works is up to your DM's personal ruling, but 'getting cut in half' is most likely not the one the game intended.

An alternative ruling a DM could use is that there simply isn't any space for the cube to form, and thus it simply doesn't form. The item description is not clear on this.