Well, does the reprobate soul spend eternity in hell or not? :) If it does, then it is immortal. I highly doubt you would say that this is a result of God's grace.
This marginal comment in particular, by John Kalomiros, a noted Greek theologian of recent times, is worth thinking about:
“I read the article by P. Chopelas carefully. I believe that it is correct. It certainly contributes to a meaningful idea of God and to a correct understanding of the nature of Heaven and Hell. ... the general concept that heaven and hell only represent how a man’s soul responds in the presence of the light of God is sound and patristic. Certainly the problem of how Christians receive the teaching of the Church on Heaven and Hell is not only a linguistic problem arising from false translations, but it is also a conceptual and cultural problem.”
“Well, does the reprobate soul spend eternity in hell or not? :)”
I meant to answer this. The answer to the question as posed is “no”. :)