Lilah, Undefeated Slickshot

Two mechanics that reward casting spells over deploying threats, welded onto a body cheap enough to make both matter. Prowess wants a deck stuffed with cantrips and burn; plot wants two-color spells you'd like to cast twice. The intersection is the design idea: cast a multicolored instant or sorcery from hand, exile it instead of letting it hit the graveyard, and it becomes plotted for a future free cast. That turns every gold spell in the deck into a delayed second use, and every second use is another prowess trigger. The tempo math is what makes this dangerous. A spell you cast for value on turn three arrives again for zero mana on turn five, pumping the 3/3 while it does, so the free spell and the attack step land on the same turn without spending your mana on either. The friction is that the replay itself is a sorcery-speed one: you set up the trigger with a multicolored instant or sorcery you cast from hand, but you cash in the plotted card on your own turn, and the spell has to be multicolored and cast from hand for the trigger to fire, which quietly rules out anything you flashed back, copied, or cast from exile. Read the trigger carefully and it is narrower than it looks; build a deck of gold burn and cantrips around it and the narrowness is exactly the point, because every card doing double duty is a card the opponent has to answer twice.