There are a lot of ways to kill demons in DOOM Eternal, as almost every weapon comes with two different modules. These give you alternative ways to kill enemies or deal with specific threats. Weapon Mastery is a new system that not only rewards you for using a certain gun but gives that firearm a bonus property. These aren’t small changes, as the Weapon Mastery buffs are substantial, turning your already strong weapon into a death-dealing machine.
To master a weapon you first need to purchase all the available upgrades for a specific mod. So, if you want to master the Combat Shotgun, you’ll need to purchase all the upgrades in either the Full Auto or Sticky Bomb tree. Once these upgrades are obtained, you’ll unlock a challenge tied to that mod. So if you want Five Spot Mastery Perk, you’ll need to destroy 25 Arachnatran turrets with a Sticky Bomb.
Completing the required challenge unlocks the perk and auto equips it to the gun. Alternatively, you can seek out Weapon Mastery Tokens hidden throughout DOOM Eternal’s level. These let you bypass the challenge completely, giving you instant access to the Mastery perk. Keep in mind, you still need to have bought all the upgrades in that mod tree.
Weapon Mastery Tokens are exceedingly rare and don’t appear until the latter half of the game. Don’t expect to find a lot of them during your journey, so focus on completing weapon challenges during fights. Which one you spend it on is entirely up to you. These are meant to reward you for using a specific weapon, so there’s no wrong answer. All of them are disgustingly powerful and can easily make a big difference during a fight.
Just keep those eyes open for Mastery Tokens when you’re roaming around. Trust me, they’re worth the effort to get!