I'm not going to try to reply to everybody, so I'll do it like this.
Kassadin's early game is boring. He's uninteresting until you get Riftwalk. Nullsphere is a good example of this, because you really don't benefit from it's Silence until you get Riftwalk.
I just want Null Sphere to move, say, Blinding Dart faster, and then it's Silence can be viable to harass with from level 1.
1.5x would likely be all it needs in terms of a speed increase.
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