In Monster Hunter Stories, when facing Deviljho, it's crucial to take advantage of its weakness to the Dragon element. Arm yourself with a Dragon - element weapon. But it's not just about the weapon. You need to study Deviljho's attack patterns. It has some very powerful and wide - range attacks. So, you should be constantly on the move. Try to get behind it when it's preparing a big attack. When it comes to Monsties, choose ones that can complement your strategy. For example, a Monstie with a support skill that can increase your Dragon - element damage. And don't forget to keep an eye on your health and stamina. Use potions and other restoratives when necessary to stay in the fight and keep exploiting Deviljho's weaknesses.