One of the most important aspects of reading tarot is phrasing the question, and I think your question has an assumption that there are indeed "soul mates", which is certainly up for discussion. A better way of phrasing the question might have been, "What should I be looking for in a romantic partner?"
Beyond that, the Death card has a number of possible implications. While one card doesn't give a ton of information, It could mean, among other things, that:
- You are evolving and changing right now and should be considering that when looking for a romantic partner.
- The person in question may be going through a lot of change at the moment.
- A Scorpio person may be a good choice for you.
I don't read reversals so I'd say the same things if the card came up right side up or reversed.
Hope that helps!