While Giant Robo would certainly make mincemeat of Cologne if it ever managed to hit her... You aren't Daisuke, and you certainly don't have Giant Robo at your command. Nice idea, though.

The troll strikes you in the head while you keep yelling, "Giant Robo, Attack!" Darkness closes in.

The last thing you hear is, "Who the heck is Giant Robo? Maybe he meant 'Sheriff Lobo'...?"