Well now that ptr for 7.1 is up we find a new achievement that Is quite rare and probably not exactly like anything before: an achievement you can only get during MYTHIC Helya.
The Chosen (New) Defeat Helya in Trial of Valor on Mythic difficulty without failing the Test of the Chosen. Title Reward: The Chosen. 10 points.
And that is certainly a great title. Obviously we don't know exactly what that entails but... should be something to challenge yourself while on farm.