When you first started Dota, what abilities/Heroes did you think were stupidly OP?

My first games against bots made me think is Valve stupid? They created a hero called Bloodseeker whose ult literally just 100 to 0's you even if you run away.

One of my first online games I kept dying to something I couldn't see over and over. Lesh had bought shadow blade and then was just invis killing me and my whole team for 20 minutes straight going roughly 30-0. I tried to copy it the very next game and got dusted and died first attempt.

What was your first brutal introduction to Dota?