Stridebreaker 226631since 13.14.1 12 changes
3000g (3000g base, 2100g sell)
Heroic Gait: Dealing physical damage grants 20 Move Speed for 3 seconds.Mythic Passive: Grants all other Legendary items 2% Move Speed.
Active — ACTIVE: (0s)
Active — Breaking Shockwave: Deal 0 phyiscal damage and Slow nearby enemies by 40% and gain 40% bonus Move Speed per champion hit that decays over 3 seconds. Can move while casting.
Builds into: 
Dreamshatter
HealthDamageAttackSpeedCooldownReductionSlowNonbootsMovement
Click any two patches to compare; the current range is shaded.
− (0s)Deal physical damage and Slow nearby enemies by 40%.Gain 40% decaying Move Speed per champion hit for 3 seconds.
+ Deal physical damage and Slow nearby enemies by 40%.Gain 40% decaying Move Speed per champion hit for 3 seconds.
− Deal physical damage and Slow nearby enemies by 40%.Gain 40% decaying Move Speed per champion hit for 3 seconds.
+ Deal physical damage and Slow nearby enemies by 35%.Gain 35% decaying Move Speed per champion hit for 3 seconds.
− Deal physical damage and Slow nearby enemies by 35%.Gain 35% decaying Move Speed per champion hit for 3 seconds.
+ Deal physical damage and Slow nearby enemies by 40%.Gain 40% decaying Move Speed per champion hit for 3 seconds.