1. E4
Big-dog Tournament game (ScootaChess - aidanB1)

Witch=dead
That's based on what Black wants to do, and you shouldn't talk about possible chess moves for an ongoing game.

Would a diagonal piece be considered adjacent to another?
Yes, adjacent pieces can be both orthogonal and diagonal. Here is a diagram (from an old thread):
(inside yellow dotted line = adjacent pieces)
The witch (white) can move as a queen (orange lines), jump like a knight, or jump orthogonally and diagonally two squares (orange dots). The witch is transparent to friendly pieces and makes all adjacent pieces (friend and foe) transparent to friendly pieces. This means in the diagram the white rook can capture the black queen. If it's Black's move, then the d4 pawn can capture the witch.
This is a bulldog with witch playoff-game between ScootaChess and aidanB1.
Game rules for bulldog with witch can be found (here).
The opening board is here:
ScootaChess plays White. Good luck to both players!