101Leafy researched the games.
Exterminator Bow I

Black Bow with an evil dragon's power. One draw of the bow is cause for chaos.
| Class | Bow |
|---|---|
| Rarity | 8 |
| Attack | 312 |
| Affinity | 20% |
| Defense | +15 |
| Slots | 1 |
| Price | 80,000z |
Upgrades
| Upgraded from | Black Bow II |
|---|---|
| Upgrades into | Exterminator Bow II |
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 802.
Materials
Fatalis Horn ×4, Fatalis Scale ×2, Fatalis Shell ×1