These 3 character variants are earned in a type of event where guilds ("coalitions" is the term used in the game) compete for the highest score. I really need to find a new guild, as too many of the good players left my current one, and the people left can't get enough points to earn the 5-star character prizes. In a lot of the event missions, I end up doing over 50% of the damage to the objective, which isn't a good sign because my tanks and crews aren't fully upgraded and spec-ed out like how the really good (or rich) players set things up.
In any case, these outfits are all pretty, and Darj looks particularly amusing with the pancake themed costume!