I will do a treasure Hunter guide too. To start with, the blue key has a chance of dropping on 11-2 and 12-5 respectively. You should have around a 1/5 chest drop chance of acquisition. Jiao doesn't appear for me before 16-5. First card with an ability drop is fairy at 16-2. I have silver blocks in quests before that so I may be wrong. After Tomorrows event finishes, I will burn potions on unlocking all quest blocks and give a full case study.