Goat format ruling
Bad Reaction to Simochi

Card effect (current official text)As long as this card remains face-up on the field, any effect of increasing your opponent's Life Points is changed to inflict the same amount of points in damage to your opponent's Life Points.
Rulings
- If you have this card and Snatch Steal on the field, the opponent will take 1000 points of damage during each of his/her Standby Phases and you still control their equipped monster.
- If you have this card on the field and activate Rain of Mercy you gain 1000 LP and the opponent takes 1000 points of damage.
- If the opponent activates Nutrient Z in the Damage Step, you cannot chain Bad Reaction to Simochi since it cannot be activated in the Damage Step. If Bad Reaction to Simochi was already applying on the field, its effect would apply to Nutrient Z.
- Multiple copies of this card are not cumulative. If you have 2 copies of Bad Reaction to Simochi on the field and the opponent activates Dian Keto the Cure Master, they only take 1000 points of damage.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Goat forum — sourced change requests get reviewed.