Since the Hespori attacks with both magical and ranged damage for their attacks, you will not be able to negate all of the damage. Using ‘Protect From Magic’ is a good idea, as is bringing some food. Monkfish is a good option to heal the max hit of 16 that the Hespori hits you with. You can use armor with high ranged defense and high magical defense, but you are probably still going to need some food to heal up. You might not be able to negate all the damage that the Hespori sends your way, but you will be able to hold the line if you prepare. Especially whenever it comes to the poison attacks, which will need to be countered with anti-poison.