Can someone explain why is this a brilliant?

Black to Move, Can You Find M5?

Found this mate in 5 in a recent game.

Pinned pieces pinning pieces for the win

Almost missed a mate in 3

Poison Pawn Tactic that Won the game, happy hunting.

Shouldn't this be a blunder?

Got him

Is This Position Winable? White To Move.

Could my opponent have castles in this position? (I moved knight from g5)

It’s not mate, but it wins.

Do you see why this move is terrible?