They are not fake I own them from 2 years I bought the cards from Amazon like 15$ I guess.
The Power Rangers Action Card Game utilizes the Power Cards from Power Rangers Megaforce as a collectible trading card game celebrating Power Rangers 20, the Power Rangers' 20th anniversary. As such they can be used in conjunction with the Gosei Morpher toy or in decks.
Based on the data on the Gosei Morpher there are several sounds, and thus several cards that are possibly available featuring all the past core rangers, most of the sixth rangers, several of the power-ups of each team, Megazords and the teams themselves.
I also have Ben 10 Cards, Companies do this type of marketing for the Brand Visibility, Even the Ben 10 Fighting Games one I bought was most of them played by my Younger Brother.