New Fairy Piece - The Hawk!

What does '+1' means

Not so sure about that valuation. Rook+Ferz combo is already easily 7 points. Then consider that this thing carrying a backpack nuke has crazy positional power and not only can it checkmate a bare king without the help of any other piece. It can also snipe the enemy king without the help of any other piece, and moreover, moving next to the enemy king is always winning if legal. This position is a win for white (The White Queen is a "hawk")

Black to move.

King f6

Hawk takes e6.

King g7 is forced.

Hawk takes h6.

King h8 is forced.

Hawk takes h7 mate.

Alternatively

King g6

Hawk f5

King g7

Hawk takes f7

King h8

Hawk g7 mate.

I think this piece is above queen strength and probably even above Amazon strength due to absolutely insane positional power and especially mating power. I give it 18 points of material as an absolute wild guess.