Both are vulnerable to all status ailments. When hit, each counterattacks with a Double Tech: Masa with X-Strike, Mune with a Chaos-inflicting attack. If one is afflicted with a status that will stop them from taking their turn (such as Chaos, Sleep, or Stop), neither will be able to counter. Defeating one twin ends the battle.

Keep an eye on your party's HP, as this boss's physical attacks hit hard. With a base HP of 3600, it is relatively quite strong for its early placement in the game.

When you see the message “Storing tornado energy,” you can use Crono's second Tech* to neutralize the stance (in vanilla, this would be “Slash”); any other attack during this stance will result in a lightning-based counter. Masa & Mune gets stronger after storing energy. After successfully storing energy (look for the battle message that says “Pain…” and you'll know it's about to go off), it will release it as a powerful lightning-based AoE. Fully healing your party should ensure that you survive this attack.

(*if Crono's second tech happens to be Life, this strategy is unavailable)