Servant of the Conduit

A green two-drop that arrives with exactly enough charge for two activations, then falls silent until something refuels it. That is the whole constraint: it ramps and fixes any color like Llanowar Elves with a wider palette, but each mana taps the creature and spends an energy counter, so the "any color" line is rented, not owned. Two activations off the enters trigger, and after those it is a 2/2 holding a dead ability. That gating ties the card to its mechanic in a way most acceleration creatures avoid: a standalone mana dork earns a slot in any green deck on its fixing alone, while this one only pays off where energy is already being banked and spent for other purposes. The body carries the difference: a 2/2 for two can trade up or chip in for a swing once the battery drains, which is more than a vanilla mana elf offers when its ability goes cold. It belongs to a small line of two-drop acceleration that reaches all five colors, and it pays for that reach not with a steeper cost or a life payment but with a finite reserve. The design puts a second toll on top of tapping: energy counters are a currency the creature cannot generate again on its own, so the ability's lifespan is decided at the moment it enters, not by how often you are willing to leave it untapped.