That yes is all the Nox needs.

Its outline goes hazy as it charges towards Riddler.

The moment he's within range, the Nox wraps itself around him, legs, tail, neck, even the carousel pole becoming a flexible tendril that clings to Riddler's body.

And then it begins to thin out, the shape of the merhorse vanishing as the shadows spread to cover Riddler's body and slowly, softly, sink into him.

It won't be painful, but it will feel very cold.