If you could create a new chess piece, what would its movements and abilities be?

We've all been there - stuck in a stalemate, usually after a gruesome loss, wishing for a game-changer to turn the tables. Lately, I have been brainstorming a new chess piece. Not that it will ever be implemented smh 🤦🏼‍♀️ but if you could create a new piece, what would it be called? Discuss its ability on the board.  How can we make this piece a game-changer while keeping the game balanced? 

I’d add an “eagle” piece

Here's the rules:

Eagle does not appear on the board.
Only when a bishop is in an absolute pin, the eagle

can swipe in and pluck the King away and place it at any position on the board.

Eagle can only be used once.

Barbarians, inspired by the Dave Consiglio.

Barbarians move like pawns, with two exceptions:

Any piece that takes the Barbarian is taken down with it. This piece isn’t going down without a fight.
Barbarians can choose to sacrifice themselves to take a piece in any one of the eight tiles around it. Be careful where you place that rook…

The Barbarians take the place of the two outside pawns (sorry, OP).

Why? Traditional chess has an emphasis on control of the center. However, adding these two semi-powerful pieces to the outside edges adds a new emphasis on the flanks:

you can control the flanks and box in the powerful pieces with unprotected barbarians
you can force your opponent to take the barbarian with a more valuable piece
The barbarian can protect pieces better than any other piece in the game - attacking pieces can’t come near, unless they are of a low value such as a pawn. Interestingly, this makes pawns more valuable, since they can be used to get around barbarians. Pawns also have to be used to protect barbarians against opponent pawns!

Nightrider makes any number of knight moves in the same direction. I find this piece to be particularly interesting. The nightrider was invented by T. R. Dawson in 1925. Nightriders can participate in triple check. Nightrider is a rider or ranging piece which moves an unlimited distance in one direction, provided that there are no pieces in the way. Riders can create both pins and skewers.

Adding a nightrider on a chess board will surely make the game very interesting.

I would create a rebel. It can move one spot forward, back, and diagonally. It would appear after your king is captured. It’s goal is to capture the piece that captured your king, and become the king. Though they can capture your opponent’s king as well, and control both armies. There will be 8 of them, and they can appear on any unoccupied square. They’d rebel against the side ruling you for your independence.

The aurora. It can go two steps on all sides. If it passes through a material, the material is disabled for the next 5 moves. You can only capture it long distance, or that piece will get disable for 5 moves too.

Q

A siege piece that can 6 like a bishop but can jump 1 block of either one's own piece or enemy pieces and city pieces that can add random pieces into the board periodically.

I’d make a shield. It moves 1 square any direction and protects the king from dangers. It can’t be taken.

Can move like a bishop*