The announcement for the Cerberus Master Pack made it seem as though the "3 cerberus mounts" would all have permanent versions. However, only the purple version does, and when you get it the rarity is listed as "Uncommon". The other two versions are only dropping as 1 day and 7 day versions, and apparently the drop rate is less than 0.5% because I opened 200 packs and only got 3 permanents of the purple version and not a single of the other two colors.
Also, the gear in the pack is all sorts of mixed up. The level 30 myth gear is giving storm spells?
The reason why you aren't getting any other permanent mounts isn't on behalf of the game, it is your RNG and your luck that affects the drop. Not the pack being bugged.
