Kari Zev's Expertise

A one-turn theft grafted onto a free spell, and the design problem it resolves is that borrowed creatures usually walk back to their owner at end of turn with nothing to show for it. The loan half of this card is generous: you get a body, untapped and hasty, for a single swing. The second half is where the value gets banked. The two-or-less mana value ceiling on the free cast is the restriction that pays for everything above it, and it points the card at a specific companion piece: a cheap sacrifice outlet cast at no cost, so the stolen creature dies to your own effect during your turn instead of returning to its owner at cleanup. Because the outlet is a permanent, it survives the loan; you have attacked with someone else's threat and kept a board piece besides. The from-hand clause is the wrinkle worth internalizing, since it means the theft only converts if the enabler is already in hand, not sitting in your deck waiting to be drawn. That constraint is also what makes this the Expertise whose free cast lines up most cleanly with its own spell: several of the others reward a proactive tempo play, but a steal specifically wants a way to make itself permanent, and a two-mana sacrifice permanent is exactly the shape that fits under the cap.