This is a Vintage+ power level cube. The '+' means that it includes both custom cards, which will boost the power of certain archetypes or play patters, or upgraded (+) cards, which boost the power of the cards themselves.

In "The Edge of Dominion," we see a group of colonies working in the outer reaches of the continent, just beyond the grasp of dominion. As groups fight for power while maintaining tenuous alliances (just enough to fight back imperial incursions), many people are just trying to live their lives in relative peace. It is a wild land full of peril, adventure, magnificent treasure.