Riot really needs to learn to avoid these reworks with all the power in one skill

Take the first Cassiopeia rework, what was it that people hated about playing it? That she was nothing but an E bot with her other spells just being there to enable her spamming her E. Malzahar's rework shoved all his power into his voidlings, his E was essentially like Cass's Q. Kog'Maw's rework put all of his power into his W. Now we have Sejuani's rework where so much of her power is in her E and passive, both of which are also uninteresting for the person playing Sejuani. We also have Maokai with so much of his power now being shoveled into his E. You'll also notice that a lot of times the ability that has the most power is also the easiest ability to use or the most uninteresting one, which makes the change even further unhealthy for a good champion.

Riot needs to stop making champions so one note. This isn't to say that they should go the opposite way and make them super generalists with a bunch of things in their kit, but each ability should feel important and be powerful, even if it only does one thing. Take the reworked Warwick, he has his power much more evenly distributed around his kit and it has resulted in him not being a balance problem (At least not so far anyway).

Having one ability with all the power makes it so it's easier to find a way to abuse it and have an unhealthy playstyle and less skill expression. A champion with power more evenly distributed around their kit takes more skill and has less chance of being abusive since the player needs to use everything right to do well.

Overall, I think Riot needs to take a step back and look at how some of their reworks are turning out and avoid these kinds in the future.