Folks used to see him skulking along the north shore of Lake Zarovich, shooting lightning bolts into the water to kill the fish
(If the characters seem interested in meeting this wizard, locals recommend that they use the fishing boats on the south shore to cross the lake, because it's shorter and a lot less dangerous than walking around the lake)
There's a Vistani camp in the woods southwest of town (area N9). The Vistani there aren't very friendly