Skill Drain and Cyber Valley?

And this is where it gets complicated.

Skill Drain would negate Cyber Valley's second and third effect, but not the first.

Skill Drain does not negate the activation of effects, just the effects of effects. Because removing from play Cyber Valley is a cost for the first effect, it will no longer be on the field for Skill Drain to negate. For the second and third effects, it's because of Cyber Valley being removed at resolution is what makes it vulnerable to Skill Drain.

Of Course, Skill Drain Negates all monsters' effect in the field, even Giant Kozaky, it cannot stay on the field if theres no Kozaky in the field, so, if you activate Skill Drain, Giant Kozaky can stay on the field even without Kozaky.

But you must know, Skill Drain cannot negate monsters effect that activates in the graveyard. Cards like Sangan, Shining Angel and Destiny Hero - Malicious, even though they're effect was negated when they're in the field, when the get to destroy, they still activate they're effect because they're effect activates on the graveyard.

skill drain only effects monsters on the field...he can remove himself from play to end the battle phase because he removes himself from play as a cost (basically his effect activates when hes out of play)...his second however cant activate because he has to remove another monster from play to activate...its wierd and complicated but i hope i helped