Dack's Duplicate

Clone effects usually come with a tax: you copy a creature but inherit summoning sickness, and the best target is often the one your opponent is most able to remove before it does anything. This one pays that tax off twice. Haste means the copy attacks the turn it lands, collapsing the usual one-turn gap between a Clone resolving and a Clone mattering, so it works as a finisher rather than just a body. Dethrone then layers on top: when it swings at whoever is ahead on life, it grows, which turns a clone of an opposing bomb into a clock that compounds. The combination quietly reframes what copying is for. A standard Clone is reactive (you mirror the best thing in play); this version is aggressive, because the haste-and-counter package rewards copying a large attacker and pointing it at the table leader immediately. Dethrone, of course, only triggers against the player with the most life, so in a duel it lives or dies on the life totals, which is the restriction that keeps the +1/+1 counters from being free. The 0/0 printed body is irrelevant in practice: a Shapeshifter that never enters as itself is defined entirely by what it lands on, and here it lands ready to swing.