Half-Orcs have the Relentless Endurance racial trait:
Relentless Endurance. When you are reduced to 0 hit points but not killed outright, you can drop to 1 hit point instead. You can't use this feature again until you finish a long rest.
So what happens if a Half-Orc is directed by an effect that steals its soul if it dies, such as (but not limited to) soul cage?
The description of soul cage says:
This spell snatches the soul of a humanoid as it dies and traps it inside the tiny cage you use for the material component.
If the Half-Orc dies, then this spell could be used as a reaction. If the Half-Orc dies, what would happen first? Would the soul cage steal the soul, or would the Relentless Endurance happen first and the Half-Orc would remain alive?