Buff or Nerf???
http://www.surrenderat20.net/2015/09/930-pbe-update.html#more
Riven [NOTE: These changes are EXPERIMENTAL. Few tweets for context: 1, 2, 3 ]
Runic Blade (Passive) changed to:
Riven's abilities charge her blade, causing her next basic attack to deal an additional physical damage. If Runic Blade damages an enemy champion, Riven gains 20 Edge.
Riven's damage is increased by up to 10% based on how much Edge she has. If she hasn't gained Edge in the last 10 seconds, Riven begins to lose her Edge at the rate of 10 every second.
Bonus Damage:X
Passive is now on next basic attack rather than stacking up to three times.
Passive now generates a new resource called Edge.
Blade of the Exile (R) - Wind Slash now consumes all Edge to increase damage rather than based on health missing.
Seems a buff rather than a nerf...