Again, the rationale is to identify items that require immediate attention, or that offer ready opportunities for redefinition
For example, the sagas in Doctor Who corresponded to episodes of the real-world television show, and Fallout used sagas to represent the different Vaults scattered across that world
At the same time, her Trance ability lets you mill two cards at the start of your combat phase to gain flying until the end of the turn, moving two cards per turn to the graveyard and making her more likely to hit the enemy player
Regeneration gives it resilence and makes it more beneficial for you to put it through the combat phase
(Interestingly, Valor's Reach is the name of one of the big conference rooms near R&D.) To play into the theme of people working together, like the players are doing, the battles in Valor's Reach are always team-ups