101Leafy researched the games.
FestiveRustlingRain

Mysterious Dual Blades that mesmerize the listener with its thunder clap-like sound.
| Class | Dual Blades |
|---|---|
| Rarity | 10 |
| Attack | 350 |
| Defense | +12 |
| Slots | 1 |
| Price | 135,000z |
Upgrades
| Upgraded from | Festive Fall Typhoon |
|---|
Upgrade tree from モンスターハンターポータブル 2nd G 公式ガイドブック (Enterbrain, 2008), page 714.