I'm not fond of the fact that it becomes much harder to imbue your crystal shield, bow, and halberd. That makes them relatively useless until you completed the Song of the Elves quest. Which, as has been mentioned, is not easy to do.
I would prefer that somebody who hasn't completed the quest is still able to do this somehow. Maybe remove the crystal shards from their requirement and allow Ilfeen to sing to the enhancement seed to combine it with your crystal bow?
What I found weird was that your initial statement was that you get around 50 shards per hour. Then, reading the agility course, you only get 8 per hour? This is quite a big difference.
The achievement diary is now locked behind a very difficult quest. I would suggest making the easy- and medium tier both accessible in Tirannwn, so no tasks that need access to Prifddinas.
My last question is why crystal shards are not tradeable? Currently (almost) all of the consumeable resources are tradable, such as: Zulrah scales, Vial of blood, and Lizardman fang. This simply forces people to do content they may not like every now and then if they want to use any crystal equipment or divine potions.
11-May-2019 10:01:32