Flame-Refined Talon

The Flame-Refined Talon is a boss-locked crafting material: community documentation lists it as a direct drop from Calamitas, one of the game's boss encounters. 'Direct drop' matters here - it comes from the boss kill itself rather than from chests or general mob farming, so your supply scales directly with how often you can down Calamitas.

Its documented crafting destination is a big one. The Build Reset Token - the Mythical full-respec consumable craftable at Level 70+ - requires 3 Flame-Refined Talons alongside 1 Ashen Pendant, 7 King Crocodile Scales, 5 Tough Direhide and 2 Dark Spirit Alloy. That places the talon in a small group of boss materials (with the Crocodile King's scales and Nix's direhide) that gate the endgame respec economy.

If a respec is in your future plans, start banking talons early: at three per token, every Calamitas kill you skip is a delay on the recipe. As the only Rare-tier material currently documented, it also tends to hold trading value.