Did they nerf or buff randuins?

Honestly it could be a nerf buff people that don't use attack spd or crit but do physical damage such as Darius riven randuins got nerfed against them. For people that rely on auto attacks crit such as adc's randuins got buffed because 10% piled on with the 10% mastery and attack speed slow is huge to reduce the amount of crits/damage the adc will receive late game.

Yes.

A nerf.

Previously it was your best choice for blunting the impact of AD-based champions who focused on skill damage rather than Crit. Zed, Talon, Vi, Jman, Panth, Riven, Lee, ect.

Now that basically all the purely defensive armor items are skewed toward reducing the damage of auto-attacks we really don't have any effective means to deal with the damage AD-casters put out. It's going to be even easier for Wu, Jman, and Vi to shred people down to near-zero armor.

it was a nerf with a compensation that's not good enough