Talk:Kassadin/@comment-178.238.250.43-20120321205257/@comment-76.21.126.46-20120322055141

No, he gains attack speed based on the amount of damage his passive reduces, which is 15%.

So, if he takes 100 spell damage, with 0 MR, his passive will reduce it by 15%, or to 85 damage. Kassadin than gains 15% AS (because he reduced the spell damage by 15)