Thread:Yukari 2020/@comment-27188908-20131215154616/@comment-30011748-20131215155837

Gilbert is telling you to equip the Shirogane Blade (any) and I believe get it upgraded past Rank 5. Shirogane weapons are created from branching off from the Kurogane first rank weapons. He is also telling you the Core for those weapons' creations can be made with the materials provided on the list when you select a Core in the Material Creation/Item Creation/Upgrading/Core Creation Menu.

The main part of Gilbert's quests is usually having the Shirogane Blade on hand. You can dequip it later when the Field mission he wants to go on is already accepted. I'm assuming you are used to getting the materials for weapons? The Cores can be made into a compressed green icon version in the Material Creation. This compressed green icon version is sometimes needed to upgrade the Shirogane weapons to the next level.