PvP Why is it based on power level?

Also worth pointing out that Ascension alone only increases the power level of a card by 25 points. The general forumla that we feel is correct for card power levels is this:

(level * 35) + (rarity above common*25) + ((number of traits)^2) * 50)

Source:

Getting a Kingdom to level 10 gives you an extra 40 points of Power Level, and a single mastery point gives you around 4.33 Power Level, and this counts for both Player and Guild masteries.