Arcana Force XIV - Temperance (SGX4-ENB08) - Speed Duel GX: Midterm Destruction 1st Edition

During damage calculation, in either player's turn: You can discard this card; you take no Battle Damage from that battle. When this card is Summoned: Toss a coin and apply this effect. The effect lasts while this card is face-up on the field.
• Heads: Halve all Battle Damage you take.
• Tails: Halve all Battle Damage your opponent takes.