Step 6 - Formation of Last Two Edge Pieces #11 & #12
You will quickly realize that it is not possible to solve for the #11th edge piece using Edge Piece Series & substitution method. There is nothing left to substitute with. We need a different approach.
RIGHT POSITIONING
Cube below is a typical ending you will should get. There are other variations, so you need to understand the method. In this cube, note the edge series with the FLIPPED pieces, it is the vertically edge. The end of Zoro's sword on the right circle belongs in left red circle.
In this case, we need to invert the entire edges pieces upside down with the end of Zoro's sword. Picture below show how you can use an Edge Piece Series to move the row of edges up, and then FLIP / INVERT it back into it's original position using another edge series.
What you want to achieve it this. If this row of edges is already originally as such shown below. This step of removing & inverting the row upside down is NOT required. Why? You'll see later.
KEY MOVE
This is the most KEY move... the 180 degrees rotation of Zoro's plane to bring the entire row of edge pieces with the inverted pieces opposite & upside down.
This is cube below is what you get. Now switch over the end of Zoro's sword... you cant see it now because it is on the hidden on most the left edge. It simple two swipe across horizontal layer as shown.
FINAL UPSIDE DOWN INVERSION
You'll get this cube now. See the Zoro's sword is fixed. The only piece left is circled red on the right. It is at the bottom, therefor we now we need to invert upside down that entire edge rows. You can do it by same technique I explained earlier.
The cube below is now having that upside down Zoro's sword in the vertical edge. You can see it is now upside down and ready to accept the last piece, the hilt of Zoro's sword. Another last two horizontal swipe.
All broken edge pieces and combined properly in its respective rows!
