101Leafy researched the games.
Plesioth Crystasword

Not merely a Sword, this crystal weapon launches a jet of water upon contact.
| Class | Great Sword |
|---|---|
| Rarity | 4 |
| Attack | 672 |
| Water | 470 |
| Slots | 0 |
| Price | 6,350z |
Upgrades
| Upgraded from | Plesioth Watersword |
|---|---|
| Upgrades into | Plesioth Azureblade |
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 682.