User blog comment:RoznosicielCiast/Least popular champions/@comment-4061583-20130124222714/@comment-5514182-20130124230507

Viktor's problem is his short ranges and hard mechanics. People complain about his passive being useless, but it gives 99 AP for only 1000 gold.

Xerath's problem is that he is reliant on his ultimate (although low-cooldown) to do the most damage in a teamfight, and the enemy can take advantage of that.