REDU format ruling
Twin-Shield Defender

Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)When this card you control is destroyed by battle and sent to your Graveyard, you can halve the current ATK of 1 face-up monster your opponent controls, until the End Phase.
Rulings
- Twin-Shield Defender's effect targets 1 face-up monster your opponent controls.
- Twin-Shield Defender halves the current ATK of the targeted monster, including any gains and/or losses from effects.
- Example 1: Sangan equipped with Axe of Despair has 2000 ATK. If its ATK is halved by Twin-Shield Defender it will have 1000 ATK.
- Example 2: Sangan's original ATK is halved by Shrink to 500 ATK. If its ATK is halved by Twin-Shield Defender, it will have 250 ATK.
- If Rush Recklessly is activated after Twin-Shield Defender's effect resolves, the ATK gained from Rush Recklessly is not halved.
- If Shrink or Megamorph is activated after Twin-Shield Defender's effect resolves, Twin-Shield Defender's effect disappears.
- Example 1: If Sangan's ATK is halved by Twin-Shield Defender to 500 ATK and afterwards its original ATK is halved by Shrink, it will have 500 ATK.
- Example 2: If Sangan's ATK is halved by Twin-Shield Defender to 500 ATK and afterwards it is equipped with Megamorph, it will have 500 ATK or 2000 ATK (depending on Life Points).
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.