Signature Swap (Light Deck Mod)

Setup: After mulligans, each player secretly chooses one nonland card from their opening hand and sets it face-down in a “Signature” zone. Draw back to 7.

Rules: Once per game, during your main phase, you may reveal and cast your Signature without paying its mana cost; it gains “if it would go anywhere, exile it instead.” If countered, it stays exiled (still counts as used).

Balance Knob: If power levels vary, require an extra cost of discarding a card to cast the Signature for free.