Forum:Stardust AM vs Royal Oppression

More questions regarding Stardust Assault Mode.

1. Can Royal Oppression be chained to Assault Mode Activate and negate the summon on Stardust Assault? If it can, can Stardust chain to Royal Oppression and negate it? Then would Assault Mode Activate still resolve and bring out Stardust Assault Mode?

2. Can Royal Oppression be chained to and negate the summon of Stardust Assault Mode after it has negated a spell/trap/effect and is attempting to return from the graveyard by it's effect?