Here is the full list of all 23 Umineko When They Cry - there are Answer Arcs achievements.
Complete the EP8 Hidden Tea Party
Complete the EP8 Tea Party
Ending B reached.
Find the culprit without any hints.
Get every medal.
Something’s different this time...
Complete the EP7 Hidden Tea Party.
Complete the EP7 Tea Party.
Complete EP7.
And so, the tale begins.
Complete the EP6 Hidden Tea Party.
Complete the EP6 Tea Party.
Complete EP6.
They cannot save you.
Complete the EP5 Hidden Tea Party.
Complete the EP5 Tea Party.
Complete EP5
Battler jumps out Kinzo’s window
Ending A reached.
Master EP5-8.