Can Onslaught's GE be negated?

[Fractales]

Kind of a weird one. I thought I'd ask about it specifically.

https://overpower.ca/code/GE

[chuu]

i think that KO part would still happen as it's a cost to playing the card but the benefit would get negated.

[Fractales]

Seems like the whole sequence would have to be negated, similar to how negating Fortress of Solitude cancels the concede.