User blog comment:JBox2D/Deleted/@comment-7709681-20140930002240/@comment-24090662-20140930012319

You're forgetting two things:

1) It's literally only useful if they step on a trap since you have no other way of putting the passive on them without that. You have a maximum of 3-5 traps depending on level, and they can be cleared. The actual frequency with which it is available to be used is very low, and the chance of actually wanting to use it on that target lower.

2) It doesn't have a seperate cooldown from the normal gapcloser version of the ability: using it globally means that you don't have your ordinary E for a very long time: no gapcloser, no real escape. That's why the cooldown's low: if it weren't, using it globally would basically always hurt you more than it helped.