Here is the full list of all 48 Dynasty Warriors 8 Empires (JP) achievements worth 1,000 gamerscore.
Won a battle with significantly less allied forces than enemy ones.
Built a facility for the first time.
Received a weapon or item as a gift for the first time.
Cleared any scenario on the "Chaos" difficulty.
Completed four Battle Objectives in a single battle.
Swore a sworn sibling oath for the first time.
Had a child for the first time.
Got married for the first time.
Professed your love for someone or had someone confess their love for you for the first time.
Obtained 20 officers in your own Kingdom.
Fought and win a stage in spring, summer, fall and winter.
Completed a Strategy Objective for the first time.
Won a battle with more than 90% of your total forces remaining.
Stopped a Large Scale Stratagem being prepared by the enemy.
Completed your first mission.
Accomplish all of the achievements in the game.
Complete all lifestyles.
Achieve all titles.
Obtain at least 100 weapons.
Obtain at least 30 items.
Use any custom character to defeat all of the famous officers.
Defeat more than 10,000 enemies using just Stratagems.
Execute all Strategy Commands at least once.
Have a total of at least 5 children.
Make all famous officers into your subordinate officers.
View all of the events that can be watched in the Gallery.
View any of the endings using a custom character.
Succeed your superior's position for the first time.
Became a Ruler for the first time.
Get recruited as a Marshal or Strategist from being a Free Officer.
Rise in rebellion and become Ruler.
Raise the banner of your own Kingdom for the first time.
Create a Kingdom comprised entirely of your sworn siblings, spouses and children.
Perform a betrayal for the first time.
Have a subordinate officer abandon you for the first time.
Fight your way into enemy territory alone and defeat an officer.
Use a Stratagem to change the weather.
In Edit Mode, create at least one officer, banner, warhorse and soldier.
Use at least 100 Stratagems.
Be appointed as a Strategist for the first time.
Be appointed as a Marshal for the first time.
Take part in "Battle of Chibi - Allied Forces" & have Zhuge Liang's "Southeast Wind" strategy work.
Capture 10 or more bases during a single battle.
Obtain virtue of "Saint."
Obtain virtue of "Pure Evil."
Complete a Quest and deepen your friendship with your Ruler.
Have at least three officers declare their love for you in a single lifetime.
Build at least six of the same facility.