its droprate is korean rng for sure. totally unhuman to make unlucky players fight the same npc like 300 times to win a single card which you only can use 1 5 star card EVER in deck anyway. totally stupid design. just another hidden rng that you cannot fix no matter what you try. i beat king now over 200 times and bought countless goldpacks. got all 8 cards from then now and still no bahamut. unfair rng is unfair. rng = reward in this game. effort is not really rewarded for most players....