101Leafy researched the games.
Twin Nails+

Painful training is required to wield that which turns your arms into fire and ice.
| Class | Dual Blades |
|---|---|
| Rarity | 8 |
| Attack | 252 |
| Slots | 0 |
| Price | 90,000z |
Upgrades
| Upgraded from | Twin Nails |
|---|---|
| Upgrades into | Fire and Ice |
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 716.