>>6 Whoops, nvm. It does show on the screen. Guess I just never noticed, teehee.

FYI to everybody, when you beat the boss, check your quest inventory for the Mysterious Xenochromatic Crystal. I don't remember if the game shows you obtained it on your screen right after beating the boss on the 1st try, but when I beat it the 2nd time, it didn't show. However, when I checked my inventory, it was already in there, so don't assume like me that the boss didn't drop it after killing it.

>>4 Hi anon 1 here I read online that the big jellyfish drops 1 crystal a day and when you sell 3 to the helmsman (or what’s it called) you get an achievement

>>3 Hi, same person who wrote anon 2 and 3 here for the final update; there ARE two mysterious xenochromatic crystals. I had to fight Chassanion twice. Maybe it’s a glitch, or maybe something regarding the game’s code says that you can only have one crystal at a time considering that I sold mine between the fights. Regardless, there are two. I can’t prove it because I only have one but keep trying if you want it I guess?

>>2 upon a second look; I did not get the item. I’d have to assume it to be a glitch considering it was the same enemy and still in the Morte Region… I’ll fight the boss again in the next server reset, about an hour from now. Hopefully that helps to prove whether or not you can get this crystal from Chassanion. Still, there’s a precious chest and an achievement.

>>1 Can confirm. Specifically, swim down and enter through a dialogue option, should see a header specifying bottom. Swim downstairs. It gives the achievement ‘Chassanion’ and a precious chest.

Found a second huge jellyfish inside the submerged tower, that drops a second crystal.