There are very few ways to actually lose energy counters outside of spending them, but it is possible with stray cards like Suncleanser and Final Act
Id also be remiss if I didnt mention the planeswalker that should be on every colorless builds mind, Ugin, Eye of the Storms
Livio, Oathsworn Knight 1 Cool looking card but too mana intense and lacking in combat potency for cube interest
Stack multiple reduction effects, and suddenly your opponent's math completely falls apart
Every time you play a threat, chances are good that there are two more threats and and answer being played across the table
During this era, collectors and players were provided with a variety of cards and options to build their decks and develop their strategies