Hello. As you can see, Kellan is supposed to destroy the cards you don't choose, which would send them to your graveyard.
This is the first turn. Nothing in the graveyard yet, of course.
Here he is, about to attack. The prompt comes up, I select the card I want, which should send the other 3 to my graveyard.
Unfortunately, when I look at the graveyard on my next turn, the graveyard card count still reads zero, when it should read at least 3.
Having the same experience. Bummer! That card is killer.