Loading…
You and target player exchange control of the creature you each control with the greatest mana valuemana valueThe total amount of mana in a card's cost, ignoring colour. A card costing 
has mana value 4. X counts as 0 except on the stack.. Then exchange control of artifacts the same way. If two or more permanents a player controls are tied for greatest, their controller chooses one of them.
Hover an underlined rule to see what it means.
Read from the rules text. A card that enables a keyword makes or is the thing; a card that rewards it gets better when you have it. Two cards interact when one enables what the other rewards.
