Energized effects increased and slow decays over a longer period of time.
Right now, the only champion who's really buying Stormrazor is Kai'Sa, which is mainly due to its stat profile than its Energized passive. We want players considering it for its unique effects too.
GIVES YOU WINGS : Energized effects are increased by [30%] ⇒ 35%
SLOW BURN : Energized effects slow the target by 40%, decaying over  ⇒ 1.5 seconds
Given that Stormrazor's update shifted it from a rush item to a late pickup, we erred on the side of undershooting its power to make sure it was a clearly less attractive first buy. But now, it's too weak, so we're buffin' it.
ATTACK DAMAGE :  ⇒ 60
ATTACK SPEED : [25%] ⇒ 30%
Now amplifies your Energized effects and causes them to slow the target. No longer grants a guaranteed critical strike after not basic attacking for a few seconds.
Stormrazor was created to support marksman playstyles that focus more on kiting around a fight than attacking at full uptime, but ended up becoming the predominant first item in crit builds due to its combination of early impact and crit scaling. We're keeping the idea of "occasionally super-powerful attacks" but moving it from the crit system into the Energized system so it's not just a bumper on the front of Infinity Edge builds.
TOTAL COST :  ⇒ 3100 gold
| BUILD PATH :
||B.F. Sword + Long Sword +
||[Long Sword + Dagger + 550 gold]
||Kircheis Shard + 850 gold
ATTACK DAMAGE :  ⇒ 55
ATTACK SPEED : [35%] ⇒ 25%
ENERGIZED Movement and basic attacks generate Energized stacks. At 100 stacks, your next basic attack deals 65 bonus magic damage on-hit and slow the target by 40% decaying over 1 second
STORM Your other Energized effects are 30% more effective and also slow their targets by 40% decaying over 1 second
STORM'S EDGE No longer causes your next basic attack to critically strike for 140-200% (at 0-30% critical strike chance) and grant 20% bonus movement speed for 0.75 seconds after not basic attacking for a few seconds.
Guaranteed crit damage decreased below 30% crit. Attack speed increased and attack damage decreased.
The high amount of upfront damage in the game is something we've been looking to dial back. Last patch we trimmed a lot of the burst damage from various runes; this patch we're looking at items.
ATTACK SPEED : [25%] ⇒ 35%
ATTACK DAMAGE :  ⇒ 60
| CRITICAL STRIKE MODIFIER :
||(at 0-30% crit chance)
Cost decreased. Attack damage decreased. Attack speed decreased.
Cheaper items (with fewer stats to compensate) should help marksmen reach a reasonable spike earlier.
TOTAL COST : [3200 gold] ⇒ 2800 gold
| BUILD PATH :
||BF Sword + Dagger +
||[Pickaxe + Dagger + 425 gold]
||Long Sword + Long Sword + 500 gold
ATTACK DAMAGE :  ⇒ 65
ATTACK SPEED : [30%] ⇒ 25%
|BUILD PATH :
||BF Sword + Pickaxe + Dagger +
||[Dagger + 425 gold]
TOTAL COST : 3200 gold (unchanged)
| CRIT DAMAGE :
We'll be looking to make individual marksman changes in the coming patches, but we don't want to risk overbuffing them alongside item changes. To start, we're adding power to some core crit items before looking at individual champions too heavily.
TOTAL COST :  ⇒ 3600 gold
ATTACK DAMAGE :  ⇒ 75
STORM'S EDGE MOVEMENT SPEED AMOUNT : [10%] ⇒ 20%
STORM'S EDGE MOVEMENT SPEED DURATION : [1.75] ⇒ 0.75 seconds
Essence Reaver is performing pretty well on users who have some way to "cheat" extra basic attacks (Lucian's passive or Renekton's W, or attack resets), and thus get far more ability refreshes. We want to open Essence Reaver up to a few more champions without buffing it on the core champions, and that means giving more attack speed so that champions without bonus attacks in their kit can get more bang for their buck.
BUFF DURATION :  ⇒ 6 seconds
ATTACK SPEED : [30%] ⇒ 50%
For upfront burst and lots of kiting.
Marksman itemization is pretty focus on marksmen who want to stand still and basic attack. With Stormrazor, we're introducing an item for marksmen with longer pauses between attacks, whether they're kiting or just have long attack cooldowns (looking at you, Jhin).
TOTAL COST : 3200 gold
BUILD PATH : B.F. Sword + Pickaxe + Dagger + 725 gold
ATTACK DAMAGE : 70
ATTACK SPEED : 30%
UNIQUE PASSIVE : Storm's Edge: If you haven't attacked in the last 3 seconds (scaling down with attack speed), your next basic attack will critically strike for 160% damage (+1% per 1.5% critical strike chance, max 200%) and grant 10% movement speed for 1.75 seconds