In this datamine we can see that Gree is planning on another release for a set of Trinkets and Armors which is most likely spirit water however the Trinkets suggest that it may be air element instead of water.
New Fusion Booster Armors have been added to lower the cost of levelling a Dragonforged armors. The Trinkets have no indication of what rarity they are going to be so we'll have to just wait and see.
The Epic Boss Collection Event cape preview is available on the Armor that is showcased and the key that is rewarded beside it.
Here is the strange part of the update; Gree has updated the Arena files with these new "mystery" Armors. Which is only seen in the Arena on the win streak rewards. This could potentially mean that Gree is planning to give these Armors out in the near future for win streak rewards.
Note: the key on the new Arena datamine is the key for the Champions chest that contains previous War Epics. Also I have no clue what the icon on the very bottom right is, it would be helpful if someone could tell me because right now it looks like the head silhouette of a knight, if so then it is probably just an update for a new look for the player you verse in the arena....