Well I made a Acheviement post but i guess you did not watched it.
However here is the idea we had on my post:
Plan B:
Start a game as Neutral Killer, then win it being the Psycho King.
Golden Prince
Use your 3 execution charges without killing any Blue Dragon member.
Just one is boring
Change class at least 3 times in one game
Dont mess with my target
As Mercenary, protect your target from being attacked and make him pay with Rebound in the same game
Evil Desire
Win as Cult Leader/Mastermind without getting any other member dead in the game (Evil King counts as member)
Expert Killer
Kill 4 people in the same game without dying
Nope
Get occupied/redirected 3 times in the same game and get immunity
More fun with friends
Play a game with 3 or more friends
Soul Collector
Collect 6 souls as Reaper
They never saw that coming
As Sorcerer, use Circle of Death to kill 2 or more players in 1 night.
Did you really say that?
Use trollbox on someone as the Fool/Scorned and get them killed by the court in the same day.
Loyalty is rewarded
Get protection from the king 2 or more times in the same game
Peace is winning
Win a game as a Killer class without killing anyone
Totally not deliberate
As Butler, Poison the Evil King and make him die by that
Gotcha!
Find 2 or more Cult/Unseen members in the same game as the Paladin/Sheriff
Who needs chemistry?
Win a game as Alchemist without using Stoneskin potion
Expert Deceit
Get accused of treason 2 or more times and get pardoned in the same game as an Evil faction
Revenge is mine
As Scorned, get both 2 objectives killed by the court
EDIT: New achievement ideas!
Survivor
Stay alive until Day 10
We cant lose the hope
Win a game as BD with both the Prince and the starting Good King already dead
Cold Killer
As a Knight, cold steel 3 non-Blue Dragon players in the same game
Neutrals united, never beaten
Win a game as neutral, but all the other neutrals also have to win (BD and Cult/Unseen needs to be defeated by the NK)
Unstoppable
Win a game as Blue Dragon with no Blue Dragon deaths (Good King included)
Red court
Have 4 Cult members and an Evil King alive at the same time
Violet court
Have 3 Unseen members and an Evil King alive at the same time
That was fast
Win a game on Night 1 or Day 2 as any class (Scorned,Fool and Inq allowed)
Beer Tank
As a Drunk, redirect attacks to you 2 or more times in the same game
Bad luck Bryan
Die Night 1.
I need healing
Get healed 2 or more tiems in the same game
The doctor is in
Heal Nightshade/Bleeding 3 times in the same game
"Okay maybe it’d be best if you were satisfied with what you have already! SECRET ACHIEVEMENT
Be Blue dragon, then Unseen class, then Assasin, Then Mastermind, Then Assasin And finally Evil King in the same game.