101Leafy researched the games.
True Devil Slicer

A beautiful blade forged by an aimless wanderer from the Orient who soon disappeared.
| Class | Long Sword |
|---|---|
| Rarity | 7 |
| Attack | 816 |
| Thunder | 520 |
| Slots | 1 |
| Price | 70,000z |
Upgrades
| Upgraded from | Devil Slicer |
|---|---|
| Upgrades into | Wailing Cleaver |
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 692.