Morgan did catch Deimos unawares as she had intended to, her intimate knowledge of her home for the moment enough of an advantage to beat out Deimos' better strength and speed in his Hellhound form. In the moment of surprise she had gained, where his momentum was lost and his paws slowed on the cobbles, she surged forwards, using the opportunity given to reach and touch his back, her fingers barely reaching fur; they did, though, so she called: "Tag!"
Was this unprofessional in front of her citizens? Maybe so, but it was fun, and she so rarely had that.
Now he would chase her and she was confident he could catch up, in a straight forward battle of ability. Morgan would need to be creative; she turned on her heel and ran to the side, to a small alley consisting mostly of steep steps, leading up to a higher street; hopefully the steps might give Deimos more issues than her; at the top there was a small gate, which she vaulted over easily, trying not to stop at all before heading down the new route.