Usually, two souls couldn't possibly coexist in the same body. They would constantly clash with each other until one of them would beat the other to take over the corpse. It was also the same case for two consciousness. They wouldn't fight like the souls, but they couldn't interact with each other either. Having two people that could communicate in the same body would be quite strange after all.
And it was something extremely rare when someone could interact, even once with another consciousness in his or her body, so what Eden heard back then was like a miracle.
Though, if it was a good or a bad miracle, only time could tell.
But the fact that this voice said that he needed to stop if he didn't want to die was leaning the balance toward a good miracle.
Eden could have indeed died if this voice didn't warn him at the right time, and he was thankful for that.
