To best exploit Basarios' weaknesses in Monster Hunter Stories, first, equip water - based weapons. These will deal extra damage due to its water weakness. Also, try to stay close to its underbelly when attacking as it's a vulnerable area. And don't forget to use items that can inflict status effects like poison, which can further weaken it during the fight.
Basarios is weak to Water element attacks. Using water - based weapons or skills can deal more damage to it.
Use Thunder - element weapons to best exploit Tigerex's weakness.
Equip water or ice weapons and use attacks related to those elements.
Use Ice - based weapons and attacks.
Use ice - type attacks and aim for its legs.
Equip Ice - element weapons to exploit Rajang's weakness to Ice.
To exploit Rathian's weakness to the Dragon element, use weapons or attacks with Dragon properties. For example, a dragon - element sword or a special move with dragon damage.
To exploit Barroth's weakness in Monster Hunter Stories, use water - based attacks. You can equip water - element weapons or use Monsties with water - type skills.
Use fire - based weapons or skills to target its weakness.
To defeat Basarios in Monster Hunter Stories, focus on attacking its weak points. Try to break its rocky parts.