Edge Attack on Mino castle

Figure. 1 is one position in my game (when I was a high school student).
Mino castle is hard. What do you move in this position?

figure. 1

Mino castle is so hard against side attack.
In that case, edge attack is an effective technique.
It is often said that, "When you have some Pawns and a Knight, you have a chance to attack the edge of Mino castle."
Then I moved P-9e(figure. 2) in figure. 1.

figure.2

After figure. 2, the game proceeded Px9e, P-9c, Lx9c, N*8f (figure. 3).
This N*8f is technique, it commonly occurs.

 

figure. 3

After figure. 3, the game proceeded S*8e, N-7g, Sx8f, Px8f, P-8d, P*9d, Lx9d, Bx8d, L*8c(figure. 4).
It is a knack in order to get better in shogi that you think the move of not escaping the Bishop in the position like figure. 4.
Can you find decisive move in figure. 4 (3-move calculation)?

 

 figure. 4

I moved S*9c, then Nx9c, +R6a (figure. 5).
In figure. 5, the opponent's castle is ending form at once. Edge attack on Mino castle is very effective as like this.

figure. 5

In figure. 5, if the opponent would take the Dragon, I will mate with S*7c, K-7a, G*8b.
Then the opponent moved Lx8d (figure. 6).

In figure. 6, I mated the opponent's King.
Can you calculate?

figure.6