Modernizing Swain
Preface - I have been a Swain main for the majority of my LoL career and estimate that I have played around 600 games as him since he last received any attention -At All- from Riot to the community. From this experience and understanding of him, I am going to make this discussion focused on how to update his kit to fit the current state of the game as Riot continues to rework the "simpler" champions to the standards of having flexibility and being smoother to play.
Passive: Carrion Renewal - Being able to regen mana through last hitting is an awesome thing to have in a champion as it provides an emphasis on a relevant mechanic to old and new players of all skill levels. This passive has more controversy than any other parts of this champion (even more than whether or not Phreak will strike again with calling his W Nevermore) because there is a lack of understanding of Swain. His abilities have really high mana costs for what they do regardless of how you look at it, unless you take into perspective how much mana will be renewed through last hitting. Allowing this champ to CS is very dangerous as it lets him pay for the high costs of his abilities. However, this causes a problem of snowballing. His laning phase is naturally weak due to these costs if he is being bullied, but this phase can also be his high point if does not have enough pressure on him to make him give up creeps. Riot tends to favor snowballing consequences (#LeBlanc. Katarina, Zed, Riven, old Fiora, Nasus, Jinx, Vi, etc.), but I do not. Additionally, diversity needs to continue to be a staple in development and forcing Swain to buy RoA because his passive gives regen to compensate for high mana costs is not ideal. To fix this, I would have his passive give him max mana. This would create a predicament of deciding to go max mana for big fights or mana regen for laning.
Q: Decrepify - Laser Bird has been a ability that almost does not feel like one. This move serves two purposes: to assist in last hitting minions due to its instant damage and to slow a target to guarantee a Nevermove landing given that the enemy does not use a gap closer. The reason why the damage is negligible is that the tether range is as long as its casting range. A great comparison would be to Fiddlesticks' tether mechanic on his Drain where the tether range is actually longer than the casting range. The implications of this is that it makes it a punishing spell to be in range of whilst allowing for direct control on how much damage Riot wants it to deal because of more consistent amounts of procs. Instead, people just run in the opposite direction as soon as it is on them and only suffer one proc every time pretty much. To compensate, all that would need to be done is to have the instant damage aspect of the ability removed. By removing that QoL (quality of life), Decrepify does not give the skill cap a buffer, which is a great start to updating him to the new champion standard, and it gives more all in potential to help give this Big Bird more identity than just his appearance on Sesame Street [btw Rito, Big Bird skin needs to happen... the people have been waiting].
W: Nevermove - This has been the shining light for all Swain mains: (for the most part) the only chance to outplay. It allows for catching people out, escaping, engaging, disjointing teamfights, farming, and zoning. The only issue I have with this ability is at a rather odd combination of range and damage as it does not reach far enough to be an impending threat nor deal enough to be real punishing. Where it is at now leaves it to be used quite similarly to a reversed gap closer. Almost an Ezreal Arcane Shift in the application of minor damage along with a distance differential. In my opinion, Swain should move towards either being a damage or utility mage a bit more in order to fit the game. This would be a perfect spot to do so by either shortening the range whilst upping the ratios or doing the opposite of those two.
E: Torment - The epitome of what Swain is about, Torment gives the single target damage that consequently will provide the healing needed to fight. The only thing that I would change is its interaction with Ignite (it also gives a %increase to it) and its %increases to his champion abilities in order to compensate for all changes. My reasoning for this is that the ability has travel time to allow for reactions to make it fair, it deals an appropriate amount of damage on its own, and this gives outline to how he interacts with opponents in fights. By giving it interaction with ignite, players are highly pressured into taking ignite instead of allowing for diversity for strategies such as Chilling Smite, Teleport, Barrier, Exhaust, and Cleanse. One thing that is under-appreciated about this interaction is how it forces Swain to focus on a single opponent whilst being close to others for leeching, thus making a great level of depth to understand about the team compositions and positioning of champions for what to do in the team fights. A common misconception is that you run through the enemy team laughing as you regen from them faster than they kill you. As The Swoon: you are squishy, you do not deal immense focused damage, you are short ranged, and you are a priority target. Torment is what makes these aspects exciting for all players involved.
R: Ravenous Flock - One of the hardest things for balancing a champion is deciding how important QoL is. It would be unhealthy to have another Ahri-like character dunking people because of forgiving aspects of their kit, but let's be real for a second: would it really be that terrifying to have this ability use a little more logic than just the closest 3 targets? I feel that the hallmark of this champion is being a sustain mage split between single target and AoE damage. The changes I would make to Ravenous Flock indeed would be a direct buff from QoL, but this could quite easily be made up by increasing the mana cost slightly. These changes would be to make it better for last hitting through having it prioritize minions that are lowest health and making it more predictable by having it give priority to anyone with Torment on. Together. these would make his kit more reliable, which has been an important trend in changes to champions for quite some time now.
Ultimately, I have no control over Riot's development, but I would love to hear what other Swain mains think about his kit because he is long past the point of being called a sleeper champion: he is full blown dormant. Most intricacies have to be figured out for yourself with this guy and so I would find it intriguing to hear more perspective. Thanks for reading this lengthier post and good luck on the fields!