One of the best champions in League of Legends after the 12.10 patch changes, which changed the MOBA metagame in a mostly positive way, Janna became the champion with the best win rate in the game: 54%). Many people expected her to get strong again in this patch, as the character's buff already indicated huge improvements to Storm's Fury.

At the same time, the healing nerfs, and reduced shields took a toll on her main Janna rivals, while the champion was barely affected by these changes due to her gameplay characteristics. As she will not receive any changes in patch 12.11, and none of the ADCs will be hugely affected, Janna should be one of the top picks to climb the ranked queues over the next few weeks.

Janna, a champion as easy as she is effective
The purpose here is not to make a guide but rather to explain why Janna is so strong quickly. When the champion is used with the Glacial Enhancement rune, which creates a slow zone when immobilizing an opponent, the champion becomes extremely powerful. This rune is quite strong in bot lane, as sharpshooters and supports are often close together, so putting a Crowd Control on one of the two also becomes safe to slow down the rival champion.

With her slow activated on W (Zephyr) and hitting her opponents with Q (Howling Gale), Janna can easily set up her Crowd Controls. It slows the opponent down first, then sends out its tornado when they can no longer dodge. By combining slow and hit durations, if Janna and her ADC have the range advantage, they can put a full rotation of their spells on an opponent without them being able to respond. Janna's shield, like the others, has had its absorbency reduced, but the AD (attack damage) bonuses she provides are unaffected.

How to fight Janna's power
Healers (healing-focused champions), who are generally a good response against Janna, take the brunt of overall healing and shield reduction, while Janna is only partially affected. Mages focused on pokes or burst damage might be a good answer, although Brand is getting a nerf in 12.11 that will make it less effective. Therefore, these counter picks are not as relevant these days for this simple reason.

Vel'Koz and Xerath are still good answers against Janna. Their excellent range allows them to play it safe and have enough damage to quickly destroy Janna's shield, thus preventing the opposing ADC from taking full advantage of the bonus damage. Be careful, though, as support mages aren't at their best. So while Vel'Koz and Xerath are good answers, they aren't necessarily good day-to-day champions.