Talk:Karthus/@comment-99.19.14.131-20120503132456/@comment-4184629-20120506173512

The reason you don't see people buying Rylai's on Karthus is that early it doesn't provide mana which Karthus needs deperately to be secure in his lane and later when it sees usefulness it still is only applying a 15% slow on all his moves. And yes, only 15% for everything, see Rylai's page. The RoA provides health mana and AP, everything you need on Karthus all in one item.