101Leafy researched the games.
Red Wing

Great Sword made with a Rathalos wing design. Flame Sac bestows Fire element.
| Class | Great Sword |
|---|---|
| Rarity | 3 |
| Attack | 528 |
| Fire | 150 |
| Slots | 1 |
| Price | 2,150z |
Upgrades
| Upgraded from | Bone Slasher |
|---|---|
| Upgrades into | Rathalos Firesword, Blue Wing |
Can also be made new at the smithy.
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.
Materials
Rathalos Scale ×2, Fire Wyvern Claw ×2, FireWyvern Fluid ×4, Flame Sac ×4