These are not the first, back in June and September, the two first styles were introduced, now its time for the last two to come. A different approach to the Knights of the Apocalypse that might interest you at some point to acquire them.
The Reaper 2D Style
Depicts the Apocalypse on a horse with a scythe, with a price tag of 750 Gold, can only be used on Tier VIII-X vehicles. No information on how to get it.
Retribution 2D Style
An Apocalypse Rider with a scale to maybe balance the tanks? Price tag of 750 Gold, no information on how players will be able to get it.