Uh, no?
I mean, you could, but if you want to play a DE reaper, why not just play a DE reaper from the start?
The top 20 build advice thread recommends doing this
If you follow this guide you are playing an auto-attacking melee character for what is likely to be the majority of your total playtime… which is possible, but again, I have to ask why. It’s a very different playstyle, and an auto-attacker isn’t that easy to level. (Like the guide says, it’s squishy especially at the start of ultimate. The DE reaper does not have that problem thanks to massive life steal.)