Throughout the last 2 years, Riot has been dedicating 2 periods of the year to focus on a class of champions and revamp them. Recently we had the Assassin Update in Preseason and before that, Mages were changed in Mid Season.
While Riot haven't decided what they will rework in the end of Season 7, they have stated that Diving Fighters are a strong contender for a class rework at the end of the season.
The next class in line for an update are Tanks and recently, Riot gave some insight on what they want to do with the class in general and gave some more details about upcoming changes to Sejuani.
General Goals for the Tank Update
Add more skill to Tank combat patterns.
Riot is looking to offer more points of play and counterplay and reward players for mastering these points.
Reducing the amount of reliable damage that tanks do and instead amplify their defensive and crowd control capabilities.
This is to make sure tanks are valued for the right reasons and are set apart from more offensive champions.
Making Tanks more unique.
Riot is adding more unique abiilities for tanks to effectively initiate teamfights.
While tank damage output has been problematic for a while, with tanks such as Poppy and Maokai frequently topping off damage charts, lowering tank damage while increasing utility can end up pushing tanks out of top lane and make them supports. Without kill potential and the ability to respond in trades, tanks will be no match for carries, fighters and bruisers.
Assessment of the Current Sejuani
Cool but unrealized thematic fantasy
Sejuani is a barbarian warleader riding a boar (super cool!). However in game, she lacks the cavalry fantasy outside of her Q, and does not have anything that alludes to her as the leader of her tribe.
Overreliance on ultimate
Sejuani’s ultimate is probably in contention for the strongest ability in the game. Unfortunately, it is so strong that it consumes the majority of her power budget, forcing her base kit’s output to be very underwhelming.
Lack of interesting / interactive combat pattern
Sunfire Cape has never won awards for creating deep combat patterns, so it should come as no surprise that Sejuani’s current kit is lacking in this department.
Lacks a unique identity
Her biggest claim to uniqueness is: "Has a ranged Amumu Ultimate". This falls far short of how unique we want our champions to be.
Goal of the upcoming update
Tap more into the cavalier / warleader fantasy
We would like to have moments where it feels like Sejuani is actively leading and inspiring her allies.
We would also like to add more elements to her kit that alludes to the cavalier fantasy who is always on the move ready to rush in on her opposition.
Create a more engaging base combat pattern
We want to make her base pattern more engaging and worth mastering for Sejuani players, and also give enemies something to play around. We will be reworking her base spells so the majority of her damage no longer comes from just standing near her opponents.
This will mean that we will need to take some of the power away from her currently overwhelmingly powerful ultimate so we can give all of her base spells real impact
Create a clear and unique defensive profile
We want tanks to be defined more by their defensive mechanics and Sejuani is no exception. As we reduce the amount of reliable damage she can put out, we want to change her passive so it is both more character defining and appreciable.
Allow her to directly synergize with specific allies
We’re looking to give Sejuani ways to directly augment the effectiveness of her allies. Instead of just augmenting all her allies, we want Sejuani to benefit specific allies in ways that will make her feel like a true barbarian warleader.
In general, it seems that Riot is looking to keep Sejuani's Q and make her ultimate less impactful, in order to have more space to transfer power to her other spells. Riot wants to give Sejuani an ability that interacts with allies (probably E), so it's possible that her viability as a Support might increase as a result.