Hallibaba

As the title says, the revived sky god states: The activation of this card, or its effects, cannot be negated, nor can its effects be negated.  And necrovalley says: Negate any card effect that would move a card in the Graveyard to a different place. So from my understanding necrovalley does not negate the special summon of slifer from the grave. Is this correct?

Who would you play at striker out of prime butra and otw wby and cam or would you recommend a 2 striker formation and if so which? Thanks

I was just wondering because for me banKen did well even though he often dies after using his 3 sa but if this is the case his opponent needs just one hit from Uno to die.