How do you unlock the ability to craft frostner and what materials are needed?

To unlock the ability to craft Frostner, one of the most powerful maces in Valheim, you must first progress through the game''s crafting tiers and defeat specific bosses. Frostner is a tier 4 weapon that requires access to silver, which is found in the Mountain biome. However, before you can mine silver, you must defeat the second boss, The Elder, to obtain the Swamp Key. This key unlocks Sunken Crypts in the Swamp biome, where you can gather iron. Iron is essential for crafting the Iron Pickaxe, which is required to mine silver in the Mountains.\n\nOnce you have the Iron Pickaxe, head to the Mountain biome. Silver veins are hidden underground and can only be detected using the Wishbone, an item dropped by Bonemass, the third boss. Defeat Bonemass in the Swamp biome to obtain the Wishbone. Equip it and explore the Mountains; when you are near a silver vein, the Wishbone will emit a pulsing effect and a sound. Use your pickaxe to mine the silver ore and smelt it in a Blast Furnace, which requires Artisan Table access and materials like Surtling Cores and Iron.\n\nAfter gathering silver, you will need additional materials to craft Frostner. These include Ymir Flesh, Ancient Bark, and Freeze Glands. Ymir Flesh is purchased from Haldor, the merchant found in the Black Forest biome. Ancient Bark is obtained by chopping down Ancient Trees in the Swamp biome, and Freeze Glands are dropped by Drakes, flying creatures in the Mountain biome. Once you have all the materials, you can craft Frostner at a level 4 Forge.\n\nFrostner is particularly effective against enemies weak to frost damage, such as those in the Plains biome. Its frost effect slows enemies, making it easier to manage groups or tough foes like Fulings. However, Frostner is less effective against creatures resistant to frost, such as Wolves or Drakes. To maximize its potential, pair Frostner with a strong shield and armor set, such as Wolf Armor, which also requires silver and is crafted at a level 4 Forge.\n\nFor new players, the journey to crafting Frostner may seem daunting, but breaking it into smaller goals makes it manageable. Focus on defeating The Elder first to unlock iron, then progress to Bonemass for the Wishbone. Experienced Vikings can speed up the process by preparing materials in advance, such as stockpiling Surtling Cores for the Blast Furnace or farming Freeze Glands while exploring the Mountains.\n\nA common challenge is locating Haldor, the merchant, as his spawn location is random within the Black Forest. To find him, explore the biome thoroughly, especially near large open areas. Another challenge is surviving the Mountain biome, where freezing temperatures and powerful enemies like Stone Golems pose a threat. Always bring Frost Resistance Mead, crafted at a Fermenter using Honey, Thistle, and Bloodbags, to counteract the cold.\n\nIn summary, crafting Frostner requires defeating bosses, gathering rare materials, and progressing through multiple biomes. By following these steps and preparing adequately, you can unlock this powerful weapon and dominate your enemies in Valheim.