101Leafy researched the games.
Rex Blast

Made from Tigrex. Its roar and shells are feared by wyverns. Shelling Lv2
| Class | Gunlance |
|---|---|
| Rarity | 5 |
| Attack | 391 |
| Affinity | -30% |
| Slots | 0 |
| Price | 35,000z |
Upgrades
| Upgrades into | Tigrex Gunlance, Hidden Gunlance |
|---|
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 760.
Materials
Tigrex Fang ×4, Tigrex Claw ×5, Tigrex Shell ×2, Pokke Ticket ×1