Scoring a champion takedown generates a stack, stacking infinitely. For each stack, gain 8 ability haste and 1% bonus movement speed, and reduce your size by 4%. Lose 65% of stacks on death. Size reduction is capped at 80% (20 stacks).
This augment page for Shrink Engine reflects public Arena Mayhem data for patch 26.19.
Graded against the other augments of its rarity, from all champions' games. The source publishes no per-champion results for augments.
See the Gold tier list