There are 5 DLCs per "season," and the latest one, "Castithan Charge Pack," introduces Castithans as a playable species and includes a special version of the 4-seater Raptor, a mission that will bag you a Castithan Charge Blade... to be brief, some nice stuff's in there.
If you buy all five DLC packs separately, you will end up paying $49.95 USD. However, if you purchase the Defiance Season Pass, you will have access to each DLC in the season as soon as it's available and you'll end up saving $9.95, which is basically the cost of one of the packs, essentially making this a "buy 4 get 1 free" deal.
But wait - that's not all...
In addition to the easy access to the DLC and discounted price, you will also get a couple of bonus items:
- Hellbug Combat Cap - In-game costume item
- Lock Box - In-game Lock Box