Goat format ruling
Sasuke Samurai #2

Card effect (current official text)Once per turn, during your Main Phase, you can pay 800 Life Points. If you do this, until the End Phase, Spell and Trap Cards cannot be activated.
Rulings
- If Sasuke Samurai attacks a face-down monster, apply its effect after entering the Damage Step, but before flipping up the face-down monster. The monster is not flipped. Flip Effects are not activated. Monsters like Kisetai and Giant Axe Mummy do not activate their effects.
- If Sasuke Samurai attacks a face-down monster, there is no damage calculation. Sasuke Samurai destroys the monster before damage calculation is reached.
- If Sasuke Samurai destroys a face-down monster using its effect, the face-down monster is NOT destroyed by battle, it is destroyed by Sasuke Samurai’s effect. So Mystic Tomato, Helpoemer, etc. will not activate their effects. However, monsters like Sangan will still activate their effects.
- If Sasuke Samurai attacks a face-down monster, and Ceasefire is activated during the Battle Step to flip it face-up, Sasuke Samurai does not destroy it with its effect and damage calculation is applied normally. The monster must be face-down at the beginning of the Damage Step in order for Sasuke Samurai to activate its effect.
- Q: What happens when Sasuke Samurai hits a face-down Kisetai? A: When Sasuke Samurai attacks a face-down Kisetai, its effect destroys the Kisetai before it has a chance to use its Flip Effect.
- Steve Okegawa,
- Q: What happens when Sasuke Samurai hits a face-down Neko Mane King? A: When Sasuke Samurai attacks a face-down Neko Mane King, the turn ends immediately. This is because an effect (that of Sasuke Samurai) caused Neko Mane King to be sent to the GY.
- Steve Okegawa,
- Q: When "Sasuke Samurai" attacks a face down "Spirit Reaper" is "Spirit Reaper" destroyed? A: "Sasuke Samurai's" effect destroys it, this is because "Spirit Reaper" is only protected against being destroyed by battle. In this case, it is being destroyed by a card effect.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Goat forum — sourced change requests get reviewed.