Trickster's Talisman
The equip cost is where the arithmetic bites. One mana casts the equipment, but it sits there inert until you spend to strap it onto a creature: that tax is the price of admission for the payoff, and it means the copy clause never arrives for free. What you get for the investment is delayed and single-use by construction. Connect once with the equipped creature and you may sacrifice the Talisman to stamp out a token copy of the body, triggers and all. Because the equipment goes to the graveyard as part of that trigger, the token is a bare copy: it carries none of the Talisman's ability, so the engine spends itself the moment it pays out. That routes the card through combat rather than the board directly, which makes it a beatdown enabler dressed as a value engine. On an evasive threat, or a creature with an enters-the-battlefield trigger worth doubling, one successful hit turns into two of whatever the creature was already doing, then the equipment is gone unless you find another. The friction is deliberate: aggression has to justify itself first, the equipped creature has to land damage before anything happens, and the reward is a one-time doubling rather than a repeating snowball. It rewards a deck that was already pushing damage and wants to convert a single connection into two bodies, not one hoping to grind an engine over many turns.
