User blog comment:Sifter66/Who is the most Underused/Underpowered Champion?/@comment-149.241.139.70-20130114174036

Karma and Heimerdinger, Poppy is also terrible.

As for Sej, she's actually pretty viable.

And by the way Viktor is under used because he is terrible, his passive costs too much, his CC is unreliable, and he's very difficult but not that good even if you play him well.