Who is Cloud's "inner voice?"

[Sephiroth]

There are times when all the world's asleep
The questions run too deep
For such a simple man

Cloud is constantly getting warnings/flashbacks during the first half of the story...so where are they coming from? I've thought that it was his "inner self," that Sephiroth can't control, trying to stop him from being controlled, but perhaps there's more to it than that?

Whadaya think?

When Cloud began confabulating subconsciously he activated the JENOVA-S-cells and split up his mind in one part that can fit the lie and one that does not fit the lie. So he pushed back and isolated that "truth" part in his subconsciousness. It is not that Cloud is not his "real self" (he only is not "real" in a metaphorical way, as he changed very much, didn't actually totally want that change naturally as we do, and is lying to himself while the surface does not get it as he surpresses it) as it is very well Cloud's consciousness and essence that is on the surface, which is the reason why "liar Cloud" also retained his coolness, and many other things of his normal character (can be seen and is also stated; that also was reason for Aerith to be interested in Cloud after she noticed she is more than just another Zack, she wanted to know him and him to be aware of himself fully and completely. If we go for "real" as in "normal" or "original" then it is simply Liar Cloud (that wanted to stay in that illusion but at the same time didn't know it was one as it was because of his confabulation and was the "master of his own illusion") - Lie + Isolated Cloud. He simply confabulated and replaced that part that he didn't need with the lie as that part was troublesome and that part also tried to warn him while lying in his subconsciousness as many parts of us do. The "new personality" thing is also more metaphorical than anything and was only a change of character, not "another person" literally like you and me with another consciousness making it another individual, and so had much truth remaining on the surface while the subconscious part or "personality" that knew the truth and was isolated is not even an own person with its own consciousness but simply a part of himself, another level that cries out like an echo to wake him up. A normal process of things we surpress or that simply is in our subconsciousness. Somehow it always affects us and influences us and in that case it wanted be be complete agai and get rid of the lie that combined with the okay part that remained on the surface.

So the inner voice is his isolated part that knows the truth.

It's Cloud's true and real identity, it's the real Cloud and not the fake one that's throughout cd 1 & and beginning of cd 2 before Cloud goes smurfing nuts and completely off his rocker.

Exactly the words as it is not the case. Normally the metaphoric and literal meaning is not the same. So it isn't here.