From Amazon:
About the The Dark Sea Annals series: A noble king discovers what
happens when he leaves a door open for evil. The disastrous
consequences impact generations, leaving the throne of Anglinore to a
wicked despot, the kingdom in ruins, and Aravel’s son Loch in exile. To
throw down the vile new authority, Loch will need to find the fabled
Halfainin and raise a new army from a world of reluctant citizens.
Together with his archer friend Ariana, Loch will face adventures that
span the world of Myriad, creatures that defy imagination, and choices
great and terrible all these recorded in The Dark Sea Annals.
I think the playing card is sorta showing the good king/ bad king idea.