Puzzle

Find Black's best moves

Nd6+ ?

Kb8

Either Nxe8 or Be4, let's go with the second one Be4

Also black isn't lost.

Hahaha, well, you should have said it from the start. Nd6+ was a trick move I found quickly but then the continuation isn't very sound. If black isn't lost then might as well save the bishop on f4. Then a move like Nb6+ is better, because black needs to take it with a pawn and not move the king on b8, because Nd7+ follows. So something like:

1. Nb6+, cxb6 (probably cxb6, because axb6 is losing for white in few moves.) 

2. Rc1+, Bc7 to block 

3. Bxc7 taking the bishop and removing it from f4, Qa3 only move I see saving the queen from the bishop and treatening the rook or to move the queen on white square, but I think that's even worse. 

P.S. Is it normal that the ranks are with reverse annotation or is this some sort of trick. But doesn't matter because the puzzle still can be played.

There is Re1+ in the end of that line or is there?

Yea, you are right the puzzle can still be played. 

I want to watch Carlsen vs Topalov in Cote d'Ivoire, but yes Re1+ loses the bishop. I will think about it later, is the first two moves correct ? hahaha

cxb6 is illegal. The coordinates are completely fine. The position was never intended to be realistic. 

Oh, cmon is that it, the colors of the pieces are reversed and we're done? The puzzle still can be solved, you know? Every position on the board is realistic, you just have to find the righteous path to continue the play, you can't use programs thought. 

Well the pawns are going in the other direction. Re1+ in my previous comment doesn't work due to fxe1=Q.

Obviously you are right, the annotation of the ranks and files changes everything, but I was talking that if you remove it and play it like a normal game, it can still be a nice puzzle and maybe even not losing for black. Obviously if we play it exactly as you published it, then maybe a draw?

Black does have the perpetual Nb6-Nd7, but that is too simple to be the solution. Black is in fact winning. The reverse position is as you might have guessed lost for black. Your line was fine, but both Qh6 and Rd8+ are winning for white. 1.Nxg3 hxg3 is a bit simpler, Rh8 can be answered with f3.

In mine proposition, I thought a draw is possible but I guess not. Sorry, I don't check with engines, if I did we could have avoided this whole conversation. 

On the contrary, you are not supposed to check with engine.  I did think of the reverse position when I created this. The reverse position is more interesting with the queen on c2. Now if black goes Ne3+, taking is forced and that line is similar as the one you gave and is also refuted by Rd8+. Unfortunately the actual puzzle doesn't work with the queen on f7.

Then what's the moral of this story, if black here is winning but on a dept 50 or more, and if reverse annotation white is confortably winning, then what should i take from your puzzle? 

The idea is to solve the puzzle without engine of course and if nobody can solve it I'll give the solution at some point.

I have changed the diagram into a puzzle with solution.