101Leafy researched the games.
Dual Carapace+

Sword made from 2 varieties of shell with a strong Water element solution coating.
| Class | Sword |
|---|---|
| Rarity | 9 |
| Attack | 308 |
| Water | 200 |
| Defense | +8 |
| Slots | 0 |
| Price | 85,000z |
Upgrades
| Upgraded from | Dual Carapace |
|---|---|
| Upgrades into | Dual Scissors, Twin Shells |
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 704.