Sivir has finally infected the European LCS, as the Battle Mistress made an appearance in all five of Friday's games, compiling a 4-1 record in the process. Each game also saw a team pick Sivir in their first rotation, with two teams first picking her on blue side, and three teams picking her in their first rotation on purple side.

Sivir picks and compositions, EU LCS Week 4 Day 2

Picked by Team Top Jungle Mid Support Enemy Team W/L MrRalleZ ROC Gnar Nidalee Viktor Alistar SK L Hjarnan H2K Gnar Gragas Fizz Alistar GIA W Rekkles FNC Lulu Olaf Viktor Alistar CW W Vardags UOL Shen Nidalee Orianna Alistar GMB W Niels OG Fizz Nunu Vladimir Annie EL W

The reason Sivir suits the current meta so well is simple: she aides heavy engagement and boosts rotation-based play. During a time when heavy tanks and sustained wombo-combo mages rule the rift, AD Carries need to bring self peel and offer something other than pure damage.

Sivir's ultimate, which gives her allies a 60 percent movement speed buff, allows immobile high damage carries like Viktor and Orianna, or in Fnatic's case, Olaf, to efficiently get into position. With the stacking of Ragnarok and On the Hunt, Olaf is impossible to avoid. She also allows hyper scaling mages and damage dealers to get into position to drop their massive ultimates in addition to keeping them safer.

Tanks synergize well with Sivir for a similar reason. It's hard to shirk an Alistar or Gnar engagement when it's coming at you out of fog of war at a rate much higher than you can run. Annie is also a common combination, though Origen's Mithy was the only one to bring it to the table.

Assassins also enjoy the benefit of Sivir, as it's easy to run an assassin alongside a safe AD Carry. Though Sivir has short range on her auto attack, she also has a Spell Shield to block abilities and restore mana. Her 1250 range Boomerang Blade also means she doesn't have to auto-attack to deal damage, and if she gets close enough, she can pop ricochet, enjoy the benefit of an auto-attack passive, get a few auto-attacks off in quick succession with the reset, and watch the damage stack with bounces in a team fight as she kites.

The threat of this stack area-of-effect damage will make teams choose between scattering to avoid it and getting picked off by an assassin like Fizz or Nidalee. In H2K's game, the team brought a Gragas jungle. This combination of On the Hunt and Explosive Cask gives a team options to engage and disengage at will, allowing them to completely control when and where to take a fight.

Sivir also functions as a hyper carry in many instances. In the Origen game, Niels did 10,000 more damage than xPeke's Vladimir. H2K Hjarnan's Sivir out-damaged every other player in the game. As a result, heavy shield and sustain compositions like the Unicorns' with Shen, Nidalee, and Orianna will work well around a Sivir pick. The myth that Sivir does no damage has long been dispelled, and it's not uncommon for her to out-damage other hyper-scaling AD Carries like Jinx.

It's a fact: Sivir goes with everything.

Outside setting up wombo combos and aiding teams in both creating a central threat AD Carry and adding more immobile threats, Sivir makes rotational play easy and both aides at putting down vision and reacting to it. Sending Sivir with a jungler to ward in fog of war allows her to pop her ultimate to save her teammate and disengage.

If an opponent crosses a ward, Sivir can react quickly with her team to collapse. Even without using her ultimate, her passive makes it very easy for her to stick to targets. After the pick, if the movement speed buff is still active, it's easy to get to a turret. This worked very well in the context of Fnatic's composition as they went for stacking movement speed with not just On the Hunt and Ragnarok, but Lulu's Whimsy.

In this way, Sivir also aides in turret dives. H2K used Sivir very well to facilitate dives with Fizz and Alistar and On the Hunt made it difficult for the opposition to react as Kasing's Alistar trapped them under their turrets. Pairing the bull with Sivir makes his job incredibly easy.

Krepo made a comment on the analyst desk that he's seen a rise in macro level game play, moving around the map for objectives off picks or fights. It's no coincidence this goes hand-in-hand with the rise of Sivir.

One point of controversy regarding the Sivir composition is whether or not she synergizes well with Nunu. Origen chose to pair Sivir with Nunu today to great success. The debate is whether Sivir can get the most benefit from Blood Boil. Since the attack speed bonus from Nidalee or Nunu will stack with Sivir's ultimate attack speed passive, there's surprisingly strong synergy, despite her short range.

In addition, Blood Boil isn't even Nunu's most useful feature. As Nunu lacks a gap close, he, like area of effect mages, will benefit from movement speed to use as a positioning tool for his ultimate.

Countering Sivir

Is countering Sivir even possible? Today, European AD Carries picked four different champions against Sivir. Vayne has risen not just as a counter to the health stacking meta, but also as a response to Sivir. Her longer auto attack range makes it easy to trade, and her high mobility with Tumble makes it easy for Vayne to dodge Boomerang Blade. Spell Shield also cannot block the empowered damage from Tumble or the Silver Bolt proc.

Unfortunately, outside the laning phase, Sivir's synergy with heavy engage champions makes it really difficult for Vayne to survive the team fight. It's also difficult for Vayne to keep up with Sivir's wave pushing and sieging potential. In Sivir's laning phase, her ability to shove a minion wave onto her opponent so that Vayne has to farm under tower exposes Vayne to Ricochet bounces and free damage. It also make it difficult for her to engage on Sivir lest she face heavy minion aggro.

Corki is another pick that has risen to contend with Sivir. Spell Shield will not block Gatling Gun or Valkyrie damage, his long range escape makes him fairly safe from heavy engage compositions, and his Trinity Force power spike allows him to match her damage output fairly early. Corki also synergizes well with other damage threats like Sivir does and can easily pop Spell Shields with Missile Barrage charges.

As an answer, Corki can work well, but he still won't provide the utility or deal as much late game damage as Sivir can. He also will force teams to bring another AD threat since he brings a lot of magic damage to the table.

A new threat against Sivir is the recently buffed Caitlyn. Changes on Patch 5.11 have made Caitlyn picks more attractive, and long range poke and easy wave clear with Piltover Peacemaker can make Sivir's life difficult in a 2v2. Caitlyn's threat is easily answered in a lane swap.

Though Fnatic didn't get the lane swap against Freeze's Caitlyn in today's match, their aggressive Olaf jungle pick neutralized jungle pressure. He then immediately began to make his presence known in the bottom lane to keep Freeze from bullying Rekkles and YellOwStaR.

Sivir can pressure towers from early on with levels and a B. F. Sword. Caitlyn hits her most effective spike with three items, giving her a long scale time. Before then, a Sivir composition can remove the outer ring of towers and snowball a lead for her team with the lane swap or sufficient jungle interference.

The loss

Given what I've said so far, I've set up Sivir as a pick with flaws, but very few ones. With all the utility, synergy, and damage she provides, Sivir is my choice for best champion pick in the game, and I typically am surprised when I don't see it appear in a draft. Even so, losses occur, especially if she isn't used optimally.

ROCCAT's Sivir composition mainly served to aid Nukeduck's Viktor as the primary carry. Jankos and Vander wanted to roam with Alistar and Nidalee to get early picks and snowball a lead. The early game went fairly well for ROCCAT in terms of pushing out waves and getting early towers. They couldn't find the picks in the jungle or snowball a lead.

That put much more pressure on Viktor in the late game. Nukeduck had one of his weakest weeks so far this split and seemed uncomfortable on Viktor. When the central focus of the composition cannot function, and the team cannot use Sivir to find picks early, ROCCAT didn't have many options. Even Nukeduck later said his champion pool was not in a good position this week.

sry for this week guys, i had to bad pool of champions coming in to the week. gj for enemies to abuse it — Erlend Nukeduck Holm (@nukeducklol) June 19, 2015

SK demonstrated it's possible to defeat a Sivir, but the power she provides is difficult to deny, and ROCCAT arguably lost by not using the pick optimally, rather than SK playing well against it. Even with 5.11 nerfs, Sivir is devastating. I expect to see her presence continue in Week 5 of the EU LCS and potentially decide the featured game between Fnatic and H2K, as both teams played her today.

Kelsey Moser is a staff writer for theScore eSports. You can follow her on Twitter where she tweets about Sivir in excess.