Could a Heart player intercept a Soul from a dead player before it goes to the bubbles or whatever other afterlife is out there? If so, can anything be used as a (temporary until a new body is made) vessel for them or only an "empty" juju like Cal?

I mean, ‘intercepting on death’ it’s kind of a weird thing to do? If anything, I feel you’d have better luck having a Rustblood Troll around to just commune with the Soul and let them hang around. Also of course, there’s the fact of the Bubbles being a Feferi thing and likely that not everyone goes there.