Dauntless

According to Noble 913 - "This guide is currently outdated due to the new update for dauntless reforged. You just need to get to level 10 in each of the weapon categories. They got rid of the +5,+10,+15 weapon upgrades". Also, thanks to and who upvoted this solution and I hope you found it useful.

Warning : Do not rank up drask, skraev and stormclaw weapons. I made a mistake of leveling up drask weapons to 9+ only to find out the final item required is only available through drask post missions bonuses. (elite hunt pass bonus/never downed bonus) and I wasn't lucky enough to get it. This is because the heroic version of drask, skraev and stormclaw is not available in-game yet and is yet to be released. Will cancel out this warning eventually. Credits to Healtti for Skraev and Stormclaw info.

Recommendation:
Step 1: Just play, level up and enjoy the game till you beat Shrowd and Rezakiri. You probably will have a good build and have complete most if not all monsters in the game.

Step 2: After having almost max up all the weapons, In my opinion the easiest/fastest to level up are Valomyr weapons (Radiant type). There are 5 types that required additional orbs to level up (Nuetral/Blaze/Frost/Shock/Terra), where Radiant and Umbral weapons only require Dull Arcstone as a base which can be farmed through Dire Patrols.

Items required:
Rams: Money from missions/quests.
Dull Arcstone: Receive 10 per Dire patrol mission. (need 127 per weapon to reach 10+)
Shining Arcstone: Receive 10 per Heroic patrol mission. (need 150 per weapon to reach 10+)
Valomyr Hide: Common drop from slaying Valomyr
Unstable Tailspike: Drop from breaking Valomyr's Tail
Radiant Dewclaw: Drop from breaking Valomyr's Leg
Apocalypse Horn: Drop from breaking Valomyr's horn
Fractal Hide: Rare Drop from slaying Valomyr
Galactic Shard: Epic Drop from slaying Valomyr Heroic (Also if you have elite hunt pass and never downed bonus, it has a chance to drop from normal Valomyr missions) (need 2 per weapon to reach 10+)

More info about Valomyr- Credits to gamepedia: https://dauntless.gamepedia.com/Valomyr

Level up layout for Valomyr weapons:
Creation: Ram and 3 types of crafting items (Hide, Tail, Dewclaw, Horn)
Level +1: Dull Arcstone x6
Level +2: Dull Arcstone x8
Level +3: Dull Arcstone x9
Level +4: Dull Arcstone x10
Level +5: Dull Arcstone x11
Level +6: Dull Arcstone x13 and 3 types of crafting items (Hide, Tail, Dewclaw, Horn)
Level +7: Dull Arcstone x14
Level +8: Dull Arcstone x15 and Shining Arcstone x25
Level +9: Dull Arcstone x18 and Shining Arsctone x50
Level +10: Dull Arcstone x23, Shining Arcstone x75, Galactic Shard x2 and 1 type of crafting item

More info: Valomyr itself is easy to farm after defeating most of the monsters in the game you can easily breaks its parts with a good build/team. The only grind is to get the Dull or Shining Arcstones. Another fast way to farm any orb/arcstones is to buy the bonus 100% daily patrol bonus from the in-game store but it requires 1000 platinum (real money). The bonus only helps with the first 2 daily patrol missions per day for 30 days. So instead of getting 10 orbs/arcstones you get 20 more for the first 2 daily patrol missions.

This guide is to help people to avoid the same mistake I did which is focusing on drask weapons and help grind items without switching different types of playlist back and forth. Hope this helps, and happy hunting.

Achievement description as it is in game, not sure when TA will update it.

Ach Name: "Weapon Master"

Description: "Reach Mastery Level 10 in 7 Weapons"

Mastery is viewable in "Quest & Progression" > "Mastery"

This is where you can see your current Mastery with each of the Weapon Styles (Axe, Chain Blade, Hammer, Repeater, War Pike, Sword, and Strikers). And this is what you need to bring to 10.

Select a Weapon Style using and to see an overall representation of your Mastery of each Weapon, this essentially requires you to use each variation of each Weapon to kill and break parts on Behemoths.

By using and to select a specific weapon within that Weapon Style. Here you'll see you're progress in leveling up that weapon, increasing this increase your Mastery. You (as of writing) just need to kill Behemoths to earn exp. I suggest obtaining two "ticks" on each weapon, getting 3,300 exp take a abit more time than needed.

To create variations, you'll need to acquire parts from Behemoths, which is done by atta king the limbs and having Perks such as Bladestorm equipped on Weapons. You can see what parts you need and how to earn them by visiting Wils in Ramsgate.

As long as you equip the different variations and get kills, you'll slowly make progress in Mastery, and this will probably be one of the last two you unlock.