Here is the full list of all 25 Majula Frontier: The Offense achievements.
Completed 10 missions
Win 100 arena battles
Win 35 arena battles
Win 15 arena battles
Win 5 arena battles
Win 1 arena battle
Crafted 25 pieces of gear
Completed 2 missions
Completed 50 missions
Completed 100 missions
Bought 4 town upgrades
Bought 8 town upgrades
Bought 12 town upgrades
Bought 16 town upgrades
Crafted 50 pieces of gear
Crafted 75 pieces of gear
Crafted 100 pieces of gear
Found 6 unlocks
Found 12 unlocks
Found 18 unlocks
Found 24 unlocks
Completed 500 missions
Bought 32 town upgrades
Crafted 500 pieces of gear
Found 30 unlocks