Please help! I've tried all different kinds of combos and I am first to admit I don't really know what I am doing. I read that something about poison debuffs but don't want to rebuild all of my champions. Here are my champions I have. Can anyone help me?

Also side note...there will be quests to beat a classic or tag team arena team of a higher rank and I can't figure out how to do this. I constantly lose to lower rank teams but can't win against higher! 

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