Solution: this time nobody detected every correct variation, but nevertheless there is a winner: @ralk98 found many of the key moves - congrats to your win! :)

The correct first move is

1. ... Qc8! giving the black queen many options on the dangerous diagonal c8-h3. @ralk98 and @digitalis found this move.

Now white has several options:

a)

2. Qd1 To attack f3. Rxf4! (That follows also against 2. Ra2 or 2. a7.)
3. gxf4 Nh2!
4. Kxh2 Qg4 And even the queen sacrifice at f3 cannot prevent a fast black win:

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b)

2. Nd5 Rh5! The fastest win!
3. Qd1 White has several other possibilities but none of them saves the day. Ne5
4. Re1 Rxh4!
5. Nf4 Qh8
6. gxh4 Qxh4 And white is lost.

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c)

2. Nh3 The toughest defense. Rh5!
3. Qd1 Ne5 (3. Ng5 Rxg5 4. hxg5 Qh8 and white is lost.)
4. Kh2 To protect the knight. Qf5! The winning move!

Let's consider four options now:

c1)

5. Qe1 Nxd3
6. Qd1 Rah8! White is helpless against the threat Rxh4 now.

c2)
5. Rg1 Ng4+
6. Kh1 Ne3! And black wins in every variation.

c3)
5. Rh1 Rg8!
6. Qf1 Rxh4! Black wins again.

c4)

5. Re1 Ng4+
6. Kg1 Rxh4! (6. Kh1 Rg8 And black wins.)
7. gxh4 Rg8 And white is completely lost.

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