101Leafy researched the games.
Lava Alphorn

Fire-elemental Horn. Was used by ancient people to calm an erupting volcano.
| Class | Hunting Horn |
|---|---|
| Rarity | 9 |
| Attack | 1248 |
| Fire | 270 |
| Affinity | -5% |
| Slots | 1 |
| Price | 100,000z |
Upgrades
| Upgraded from | Blacksmith |
|---|---|
| Upgrades into | Volcano Alphorn |
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 736.
Materials
ThckLavasiothScl ×8, HvyLavasiothShl ×6, Hvy Monster Bone ×8, Screamer ×8