Twinscroll Shaman
Double strike is a multiplier keyword, and a multiplier is only as valuable as the number it multiplies. On a 1/2 body, that number starts at one: the naked creature deals two damage across two hits, a rounding error next to what the keyword is meant to reward. That gap between floor and ceiling is the entire point of the design. Every point of power you attach doubles, so a single power-boosting aura or piece of equipment does not add to the clock, it scales it: a +2/+0 buff turns this into a six-damage swing, and a larger pump makes the arithmetic genuinely frightening. The frail body is the balancing constraint, deliberately cheap and small so the pump-and-attack plan stays a gamble. With no trample, a chump block eats the entire doubled strike for free, and a single removal spell in response to your buff cashes in the whole investment for one card. That exposure is the price the card pays for hosting a keyword that would be oppressive on a durable, evasive frame. It is an enabler for aura-and-equipment aggro, the sort of creature that makes cheap combat tricks read like finishers, and its worth is dictated entirely by how many amplifiers surround it. Unarmed it trades down; amplified once, it hits like something several mana more expensive.
