Total and combine cost decreased. Attack damage decreased.
There should be clear tradeoffs in itemization; in the case of Mercurial Scimitar, the extra safety from its active does not hold an appropriate tradeoff in damage dealt.
TOTAL COST : [3600 gold] ⇒ 3400 gold
COMBINE COST : [525 gold] ⇒ 325 gold
ATTACK DAMAGE :  ⇒ 50
Now on Twisted Treeline. Replaces Dervish Blade.
We covered this one up in the Removed Items section above. Go find Dervish Blade, read it, then cross this off your checklist.
EXISTS Mercurial Scimitar now exists on Twisted Treeline!
Active now only removes crowd control debuffs.
The QSS and Mercurial Scimitar active has two uses: cleansing crowd control (Amumu ult) and purging combat debuffs (Zed ult). These cases differ in that crowd control is setup, while combat debuffs are the payoffs to such setup. When you cleanse CC, the enemy needs to lock you down again to aggress on you, but that tends to bpretty reasonable ask. By contrast, cleansing a combat debuff wipes the applicator's primary means of fighting you. So, those champs are pressured to snowball before their effects become meaningless, while their opponents are forced into buying QSS even if it's incredibly inefficient to do so. This leads to destructive effects on game balance which we've left unanswered for too long. With the understanding that there may be outliers we need to address, we're unshackling combat debuff champs from their quicksilver collars.
ACTIVE EFFECT : The actives of Quicksilver Sash and Mercurial Scimitar now only remove crowd control debuffs
Cost and attack damage lowered.
Mercurial Scimitar is really gold efficient. Reaaaaally gold efficient. That’s not a problem by itself, but when tied to an incredibly powerful active in the form of Quicksilver Sash’s omni-cleanse, over-efficiency pushes Scimitar over the edge. Mercurial’s often purchased for its amazing statline alone, and its active is conveniently countering a lot of champions in the process. Scimitar’s still a great choice for a carry under pressure, but shrinking its efficiency means it makes less sense without a clear use for the active.
TOTAL COST : [3700 gold] ⇒ 3600 gold
COMBINE COST : [625 gold] ⇒ 525 gold
ATTACK DAMAGE :  ⇒ 65
TOTAL cost : 3700 gold (unchanged)
BUILD path : Pickaxe + Vampiric Scepter + Quicksilver Sash + 625 gold
ATTACK damage :  ⇒ 75
- TOTAL COST :
3800 gold ⇒ 3700 (combine cost increased by 200 gold, inherits Quicksilver Sash's 300 gold cost decrease)
- MAGIC RESISTANCE :
45 ⇒ 30
- "NEW" MERCURIAL PARITY: Active ability now gives the movement speed bonus to ranged characters as well
- ATTACK DAMAGE:
60 ⇒ 80
- TOTAL COST:
3700 gold ⇒ 3800 gold
The following changes affect Twisted Treeline and Crystal Scar only
Is a thing ⇒ Removed
Mercurial Scimitar added
- +60 Attack Damage
- +45 Magic Resist
- Unique Active - Quicksilver: Removes all debuffs from your champion. If your champion is Melee, this item also grants 50% bonus Movement Speed for 1 second (90 second cooldown).
- Cost: 3,810 (600)
- Builds from Quicksilver Sash and B.F. Sword