Patch reference

Rubick gains 1 stack of Curiosity per level, each granting him +1 base damage, +0.3% Buff/Debuff Duration, and +2 Area of Effect bonus. If Rubick sees an enemy Hero cast an ability within 1200 distance of him, he gains 2 Curiosity for 20 seconds. If an enemy that currently provides temporary Curiosity dies within 3s after taking damage from Rubick, he gains 1 Curiosity permanently