plus the 2x event bonus and if you have the diamond buy one you've got your drop.
with event bonus:
2-6 is your possible card drop count.
with event and diamond buy bonus:
4-12 is your possible card drop count.
with event bonus:
2-6 is your possible card drop count.
with event and diamond buy bonus:
4-12 is your possible card drop count.
IGN: Mythic Guild: Chaos