Spike Weaver

The Spike mechanic was Exodus's experiment in making +1/+1 counters a depletable resource rather than a permanent buff, and this is the cycle's most influential expression of that idea. The counters are not stats waiting to be admired: they are ammunition for a Fog engine. Each counter buys a turn of total combat-damage prevention, so a creature that enters as a 3/3 functions as a three-shot stack of Fog effects stapled to a body, with the option to instead deposit those counters onto other creatures when the defensive clock runs out. That payload-conversion is the design hinge. The card refuses to be dead in any phase of the game: behind on the board, it stalls combat; ahead, it dumps its remaining counters into a threat and gets out of the way. The prevention ability costs only one mana to activate, which is the detail that turned it into a control-deck cornerstone for years, a repeatable defensive lock that single-handedly neutralized aggressive starts while a slower deck assembled its win condition. The recursive defensive Spikes that followed (Spike Feeder among them) all trace back to the structural lesson here: counters that can leave the creature as easily as they arrived create a resource you spend across a game rather than a stat line you set once.