User blog comment:Supafrunk/Mana-Regen Based Champion/@comment-5284325-20121025042214/@comment-4097756-20121025150009

Thing is, it was expected to be some of sort of counter to him. The W(the mana regen stealer) also has a slow and will do some damage to all enemies, despite their usage or not of mana. Also, it's like saying that Veigar ultimate is useless because it isn't good against people without AP. A lot of champions do not build AP at all either.

As for the passive, yes it's strong. Don't worry about it I'm already considering the worse case scenario(15 stack of ultimate, Clarity, Soraka, Blue buff, Grail, etc.). I'm also thinking about reworking some of his kit, but I just got IRL stuff to do before that.