What is the easiest way to kill the fire breathing fish monsters at the end of the tower of spirits before the compass of light is found

Draw a line from Zelda to one of the Fire Breathing fish, make sure their back is exposed and accesible to you, while she is fighting and distracting him go to his back and tap REPEATEDLY on the Fire Breathing fish with stylus and link will automatically hit him. Do this to all three and make sure you have to PURPLE POTIONS. ok