Performage Mirror Conductor (DOCS-EN015) - Dimension of Chaos Unlimited

Pendulum Effect: Once per turn: You can target 1 face-up Special Summoned monster on the field; its ATK and DEF each become equal to its ATK or DEF (whichever is lower, your choice if tied), until the end of this turn (even if this card leaves the field).
Monster Effect: Once per turn, during either player's turn: You can target 1 face-up monster on the field; switch its current ATK and DEF until the end of this turn, then take 500 damage.