just finish the game and go on with start plus, which appears after beating the game once. then play with another hero to get other cards, u still have the upgraded ones, which makes it very very easy. atm i play with taurus, phantom armor, frost giant, centaur, witch and magic cannon, all lvl 5. and spells: healing wave,freeze trap, lightning bolt, athena protection, hercules strength and comet shot (for pulling their heros/best units one by one).
this game is way to easy, i only lost the first round, and i have 18/30cards. if you have beaten the game the first time its just annoying to do it again with another character, to earn all the cards.
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 "Epic War 3"){kind=icon}