As a player, half the joy of playing a champion comes from its personality and actions. Vel'koz in all honestly SOUNDS like he's battlecast already without a skin, but the extra effects, specifically the reverb, makes his voice near unrecognizable. I can't make out half the things he's saying, and I got half decent headphones.
Also, his laugh. The audio makes him looks and sound like he's humping the air. I'm not kidding! I'm reminded of a rusty piston pumping in and out!
Anyway, this is all my opinion so take it with a grain of salt.