With all this QQ about Scout and how he "breaks" heroes with invis (which is only half-true), I think I got a simple solution.

General Misconceptions about the Scout vs. Night Hound debate:
Scout is squishy. Night Hound is also squishy, but not as much. Scout takes 6 whole seconds to go invisible again. Night Hound takes 1.5 seconds. Without any way of revealing, Night Hound is more defensive. On the other hand...

The Problem:
Permanent invisibility with bonus movespeed for a negligent amount of mana. Late game, he'll actually gains mana even during Vanish. Read: bonus movespeed. This is the important part. In other words, the benefits are not balanced well by the drawbacks.

The Solution:
There's always the mana upkeep increase, but how much, no one's sure. Maybe have it a percentage? Or disable his mana gain during use? But that's for some other topic. Here's the real solution I propose.
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Vanish Effects:
- Stealth with 0.5 second fade time
- (No) Unitwalking
- +25% Movement Speed, decreasing to 0% over the next 12.5 seconds.
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Simple. It makes the Scout not always have an advantage over NH in the above situation (Revealed). Hey, he still has a manacost. Night Hound has none. Whether to keep Unitwalking or not is debatable.

But yeah, it's a simple solution I'm proposing.