I was getting nothing from Loki (literally he dropped nothing) for awhile.
I just killed him right now and he dropped a Loki card, 5 Dbl Atk/5 Atk UP Katar and a Dusk Flame. Plus I got another Loki card as a gift (maybe from my Luck UP card).
That was all from 1 run too. o_o
If you read the post about epic farming, theres a trick to this. We discovered that ur luck accumulates over time and certain things that drop will lower it as well. So if you build it up high enough your epic(or rare card) will drop indefinitely. I didnt go far into it but thats the basic idea. --- "Guess i'll logout and check my email or somethin."