Featured in a few of these precons
While the "ease of flipping" category is, in large part, a product of the number of defense counters on the battle (battles range from three to seven defense counters, and a battle with three defense counters will be much easier to flip than one with seven), it also takes other factors into consideration, like whether the battle makes creatures (if so, we can use them to help defeat the battle, making it easier to flip) or whether the battle acts as removal (which can get a blocker out of the way, making it easier to attack and defeat the battle)
The mechanic can be quite powerful, but since Kaladesh and Aether Revolt, Energy hasnt received a ton of support
these are the cards that you want to look out for
Its not something many MTG cards refer to or interact with, but Ancient Adamantoise from Final Fantasy is an exception
Final Showdown also takes out creature abilities, so your white wrath effect can get indestructible creatures, or you dont need to worry about cards that die and do something good for their owners