W damage scales up well with leveling it. Passes through minions. And when you land it first in engagement on the enemy carry at bottom it gives you an instant advantage, if you land it on both support and carry, even better, land it on your support, their support, and ad carry, even bestest.
The worst thing about it is the mp cost as you level it up. Fire it 3-4 times and you're oom, hardcore. Won't even have mp to unleash your E+ignite+auto+W+auto+Q+auto combo.
In the chronicles of my life there is a legend in which I change 'history' into 'herstory'.