Forum:Royal Oppression vs Pyramid Turtle, Mystic Tomato, Grandmaster of the Six Samurai

Hi, I have a doubt about how to use Royal Oppression, I know that Continous Trap Cards cann't be activated during Damage Step, but I don't really get how it works: If my opponent atks my Stratos with Pyramid Turtle I can't activate Royal Oppression even if He Special Summons a Monster right? but if I attack HIM? I can't activate it too?

My other cuestion i about Grand Master of the Six Samurai, if my opponent special summon him i can activate Royal Oppression and pay the 800 LP but the Grandmaster RETURNS to his hand? that's my doubt because Royal Oppression says: "Negate the Special Summon and Destroy it" so ha can or ha can't. Thanks guys