This isn't just a coincidence; it's luck. Whatever one lacks, happens to come.
Moreover, it's the top-tier King's Creation Platform.
Rosen installed the production platform he had obtained onto the Lord Interface. Upon binding, it became an interface with additional crafting functions.
He inputs the Thunder Horn he got just now; clicking the exclamation mark allows him to check the information on craftable equipment.
[Material: Thunder Horn]
——[Weapon: Lightning Rod]
[Description: Can actively shoot lightning to attack distant targets; passively reflects all lightning attribute attacks, doubling the damage]
——[Equipment: ...]
——[Item: ...]
...
It seems like the same material might be one of the materials used to craft various items; besides the current material, most of them require additional materials.
Rosen only has one Thunder Horn on hand, so he can only craft the weapon in the first slot of the list, the Lightning Rod.
