“The Emperor’s Tarot is one of the few accepted methods of divination employed in the superstitious and close-minded Imperium of Mankind. The deck is made up of cards that each have an image and a name – like The Fool and Harbinger” - warhammer-community.com
There is another warhammer game where they implemented a system for the missions that revolves around levelling your tarot deck up, and applying cards to the missions as modifiers. These are like your combat zone modifiers, but applying them not only increases difficulty but also rewards. Im sure someone at GW remembers it, it was implemented rather well.
Since the tarot deck is a part of the universe, it can be add here in a similar manner, but instead of you picking your modifiers, and leveling it up, if you choose to use the tarot deck, it will pick 5 random cards, that each add a random modifier to the mission.
Modifiers can range from increasing buffs to the different types of enemies, or detriments to the player, like movement speed, reduced wounds, etc. The occasional positive card can be added wich buffs players, increases ammo reserves etc.
Since the cards and the images are of a mystical nature, the team can have fun looking at them and interpreting what boons/punishment these cards will give us.
Accepting your fate, will grant greater rewards upon completion (loot chests, craftings mats, etc.)