Is Veigar insanely OP or was this guy hacking? I'll explain.

Okay so I'm only level 5 to start off. I was in a game with similar skill levels. I was doing well (surprise). We were rolling along took out their first 3 turrets and had the others almost down and all of a sudden this veigar comes out of nowhere and 3 hits us all repeatedly. He goes from 8-2-4 to 40ish-3-4. No matter what you did you couldn't kill him. It was bing, bang, boom dead. I honestly have never experienced anything like it. The game went from an easy win to us getting annihilated. I ended up 21-10-7. (I was probably 12-2 when this guy came outta nowhere). So, was he hacking or is Veigar really an overpowered POS champion?