it is not the only time i met this results, many times. it is called bad luck for the first time, for the second time, for the third time. but for so frequently, it is poor design.
if i spent 2000 kobans in combat, i would get much more than 1 shard, but in this mode, only 1. if i do not spend kobans, i will fail to defeat the boss, i get 0.
it is not of luck, it is of trick.
"1-x" is the crazy point, better than "0-x", but still a poor design.
"1-1X", "2-2X", "3-3X", "4-4X", "5-5X", etc, more reasonable.
otherwise, spending the kobans to get date tickets is the better way.