Elusive new raid boss?

[Ted_mutiny]

Ceto seems to be eluding me to no end. Im working on whats gotta be my 50th kill n no sign of ceto card. I've gotten ceto for at least 5 others maybe more. (5 people wrote me to say thanks for getting them the cards) Am i just super unlucky this time? I obtained previous 2 7* rb in less than 30 kills.

[cardcore]

Keep killing them higher boss level means higher chance to get it. Good luck ^^