User blog comment:StrategicMagic/The Most OP Item in League of Legends is.../@comment-3329234-20130407042217

Nasus doesn't use the Dorin's Ring is that the mana cost is low enough for your base regen to recover most of it early and most of time the mana management you need is deciding if you should use Wither and as long as you dont use anything other than Q(which you should be) then you are fine. For me usually when I reach mid game or so I have a philo/shuyrelia/Miracle(I would rush it if I think I need it. Picked almost never though) and thats usually enough for regen. I see why I can but I think I still won't pick it up. GP has kind of a similar arguement minus that he really should have mana regen items.