@dictionary The medal shop has it 1day for 100medals. Just turn in dailies and boom, easy perm Hungar. As far as boxes with Hungar go I think the best one's the Christmas boxes (2 months away from shop) bc less junk / more rare variety.
Out of the two choices listed, you'd want to buy one of the Legendary Slayer boxes. This is due to the Mystery Box Blue having more "garbage" items such as wings and 7 day accessories. But yeah, as Tengu stated, the Christmas boxes are the better bet, since they don't have any garbage items other than the timed versions of the skill items.