AP Junglers w/ Glacial Augment + Twin Shadows.
I've been playing with this for a few games and the concept 'works' but it I am not sure if it is even a good strategy that I am simply not a good enough player to use effectively.
I think the idea is pretty self explanatory. You rush the item and once you have it completed you can use the active before / while you go into the lane for a gank, slowing the enemy(ies) allowing you to get good positioning, land skill shots, or potentially causing them to use their abilities/summoner spells trying to escape. Meanwhile you still have all of your abilities available.
I think the main drawback to this is that it doesn't really add to your damage, and of course people only think something is strong if it deals damage.
So, .. I guess I'm just looking for someone to try this strategy out and tell me what they think about it.
Theoretically, this could also work with Bilgewater Cutlass, Blade of the Ruined King, Hextech Gunblade, Hextech GPL-800, Randuin's Omen, and Righteous Glory, but none of those have the range or the auto targetting mechanic that Twin Shadows has. Bilgewater, BotRK, and both Hextech items do damage, so maybe those could be better. GLP, Randuin's, and Righteous Glory are better for tanky junglers, so this could be an option for them as well.
Edit:
Rune suggestion.
Personally, I prefer to rush the Twin Shadows with this strategy. Starting with Hunter's Talisman and 3 health potions, I have been able to clear effectively enough with Evelynn to go straight into Twin Shadows, even with some invade pressure.
The Inspiration path helps with this by taking Magical Footwear and Future's Market. I also think Approach Velocity works well with this concept.
For my secondary path, I am partial to Domination, mostly because Ingenious Hunter can cut up to 35% of the active cooldown.