Is there any "OP" or maybe imbalanced heroes? Are the heroes all balanced or is there a tier list of where the heroes are ranked? Or do they all have pros and cons and slimlinic keto balance out well? I've only used Mage and Rogue so far, I prefer Rogue but just wondering in general about the heroes
It is usually more about specific decks than heroes. The success of a class has often hinged on a single card or mechanic. All the heroes (classes) have had OP cards which have required nerfs at some point in the history of the game.
RN, Hunter is the top class but has competition from Shaman, Druid and Warrior. Rogue, Mage, Warlock and Paladin are doing ok while Priest is the worst.
As SlydE said, it's more about the decks than the Heroes themselves. Although there are better cards in certain Classes than others. For example, Marsh Drake is better suited in Classes that can deal One Damage fairly easily. So Rogue and Mage for the Main.
Hunter and Rogue. They are both OP. And should be removed from the game.
XD Jokes aside, though, as others have said, what makes a hero strong is heavily dependent on the decks built around them. As such Heroes themselves are not in any way overpowered, but annoyingly they do tend to restrict the design-space in which decks can be created for them. Powers such as the Hunter one tend to lean heavily towards aggressive decks, the Warrior one towards control, etc etc.