Reflective Golem

A spell-copy engine gated behind one of the tightest triggers in the copy-on-cast family: the doubling only fires when the spell you point at the Golem hits nothing but the Golem. That single-target restriction does all the balancing. You cannot fork an effect that already touches two things, so the multi-target spells that would make a blanket doubler oppressive are quietly walled out, and the payoff stays tethered to a deliberate casting pattern. The natural fuel is a one-target instant or sorcery you want aimed at the 2/3 anyway: a pump spell, a protection spell, anything the body wants to receive. Aim it at the Golem, pay the extra , and the copy inherits the targeting rules while letting you choose new targets, so the fork can abandon the Golem to grow a second creature or, if the spell removes something, to strike across the table. The trap the design leaves open is pointing a burn or destruction spell at your own Golem to trigger it: that kills the creature you paid mana to keep around, turning a spell plus a body into a single redirected copy, a losing trade wearing value's clothing. The reward is real only when the original spell wants the Golem to survive, so the effect scales with how much your deck values keeping a repeatable, single-target host on the board. It asks for discipline in two currencies at once: mana, and the shape of your spellbook.