Here is the full list of all 26 Majula Frontier achievements.
You opened the game
Defeated the Screw Scrub
Defeated the Kzu
Defeated the Hellfire Mantis
Defeated the Plains Strider
Defeated the Crazed Behemoth
Defeated the Peerless Entity
Defeated the Sword Glob
Defeated the Monster Duo
Defeated the Black Serpent
Defeated the Ogre
Defeated the Lurcher Trio
Defeated the Devil Spider
Defeated the Tower
The Reaper
Defeated the Colossus
You saved Majula
Fully repaired Majula
Fully upgraded Majula
Unlocked All of Ellen's Friends
Defeated the Ignition Scrub
Defeated the Lonesome One
Found 25 Unique Skills
Found 50 Unique Skills
Found 100 Unique Skills
Found 200 Unique Skills