Here is the full list of all 53 FateEXTELLA achievements.
Obtained all achievements.
Succeeded 100% completion rate in the gallery.
Recorded all Mystic Codes in the gallery.
Defeated a total of 5,000 Aggressors.
Cleared all stages on VERY HARD difficulty.
Prevented a Sector Trap 30 times.
Raised 3 Servant's Kizuna level to 30.
Cleared Artoria Pendragon's hidden side mission, then defeated her, on four different stages.
Completely cleared Artoria Pendragon's sidestory.
Cleared all Servants' sidestories.
Raised a Servant's Kizuna level to 30.
Cleared Artoria Pendragon's hidden side mission, then defeated her, once.
Completely cleared Archimedes' sidestory.
Completely cleared Elizabeth Bathory's sidestory.
Completely cleared Gilgamesh's sidestory.
Completely cleared Iskandar's sidestory.
Completely cleared Jeanne D'Arc's sidestory.
Prevented a Sector Trap for the first time.
Completely cleared Karna's sidestory.
Revealed the true name of your Noble Phantasm 20 times.
Completely cleared Lü Bu's sidestory.
Upgraded one Install Skill by +20.
Completely cleared Medusa's sidestory.
Completely cleared Nameless' sidestory.
Completely cleared Gawain's sidestory.
Completely cleared Li Shuwen's sidestory.
Defeated a total of 1,000 Aggressors.
Performed 50 Moon Crux/Drives.
Completely cleared Cú Chulainn's sidestory.
Recorded all Install Skills in the gallery.
Cleared the Golden Poem arc.
Conquered a total of 100 sectors.
Allied with Tamamo no Mae in the Golden Poem arc.
Cleared the Dawn arc.
Defeated Nero Claudius in the Orchid Poem arc.
Defeated Tamamo no Mae in the Dawn arc.
Cleared the Orchid Poem arc.
Defeated Altera in the Orchid Poem arc.
Upgraded one Install Skill by +10.
Performed 200 Extella Maneuvers.
Cleared the Flame Poem arc.
Obtained an EX rank in the results.
Defeated Altera in the Flame Poem arc.
Succeeded 25% completion rate in the gallery.
Defeated Tamamo no Mae in the Flame Poem arc.
Performed a Moon Crux/Drive for the first time.
Equipped a new Mystic Code.
Equipped an Install Skill for the first ime.
Cleared the 1st stage of the Flame Poem Arc.
Revealed the true name of your Noble Phantasm for the first time.
Switched with a vice general for the first time.
Performed an Extella Maneuver for the first time.