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I generally play in the gold league, I like it because the monsters acquire a lot of abilities at the level for that league, but now that the new reward cards have arrived, the battles are more varied, I wouldn't choose to build a single deck, I would take advantage of the rentals to have more variety for my lineups.

In gold the cards gain many new abilities that greatly diversify the possibilities. It is difficult to work out a single strategy, you will need to be prepared for all kinds of opponents.