A fun way to place Keeper of the Light.
Only good when Supporting safelane.
Need a Support-player on your team to buy wards and upgrade courier.
Rush Boots and Mek/Pipe.
Pull creeps, and iluminate as mutch as possible.
Rush core items, and support your team mid/lategame.

Good Carry-Hero Combo: Sven.
If iluminate is about to hit, stunn with sven.
And then just give Sven mana.
Repeat and have fun!