Originally Posted by Myrdin

You can get a sure 2x Life crystals from current Event 40 AP map. Its the last chest.
The 80 AP Quest gives 5x crystals from the last chest so its really a good idea to farm this event as much as possible.

^ This. The skill blooms may seem underwhelming, but that's partly because they take so long to buy normally. So when events like this one, where they drop quite regularly, it's best to farm them like mad for those crystals because they accumulate at, what, 4-5 per day otherwise?