Quas Wex invoker does need some skill to be played. Autoattack damage is so small in the beginning, that i makes last hitting and farming hard. He also has many spells which he has to use in order to be useful.
And my most annoying hero in dota is ember spirit. He can be everywhere and still no where. He can also counter most spell casters with just one spell.
Quas Wex Invoker is actually quite easy with a starting claw of attack and one point in exort. Then you only build Quas Wex. Gives you a bit more spell choice in early teamfights while still giving you a strong tornado -> EMP combo.
Most annoying would have to be void. Hate how he can just decimate a team in 5 seconds as you watch, silently screaming... Plus it's your fault for letting him get that farmed :P...
Basically if you not picking a team that can finish the game in 20- 25 minutes before those clumsy heroes get BKB and rape your face at 35 - 40 minutes its your own fault for letting them farm or not finishing before the 25 minute mark
Personally i think silencer is pretty much the worst hero i can be against. He has so many devastating spells, especially against risky players (which includes me..)
Either he disarms or silences you..
He can AoE burn most manapools in a matter of seconds, meanwhile dotting the hell out of people..
He can fucking steal my intelligence!
And just to top it all off, he has a fucking global silence!
Furthermore silencer is VERY flexible, he can go almost anywhere, be any role (except for jungling), so in a CM game you never know which lane he is coming for, meaning you won't be able to counter him properly!
broodmother is good :P thats why she isnt allowed in captains mode, the problem with her is that she is not suitable hero for the metagame or pubs and she has to be changed to fit into meta.
Try playing her with dagon and eblade and you will see :)