My Attempt at a Light Kindred Rework
As is well known by the LoL community and Riot, Kindred 
is a champion that has been difficult to balance. They are an "infinitely scaling" champ oriented around late game, unlike other "infinite scalers" that are actually oriented around mid game. Kindred's performance throughout the game is entirely dependent on their ability to collect marks in the early game. If they are ever viable enough to get through early game consistently, then they are broken. Riot has nerfed Kindred specifically for being too good at 1v1 dueling in the early levels. But, if they don't have the damage or the pressure to get through early game consistently, even through simply farming the jungle, then they just feel bad to play. This leads to the champion feeling either overpowered or lacking agency, with no real in between.
Beyond balance concerns, it's also been voiced that Kindred doesn't feel as much like a dual-entity hunter as they should. Playing as Kindred mainly feels like you're playing Lamb who controls Wolf, even though their relationship is portrayed in the lore as being equal parts of the same hunter entity. Playing as Kindred should feel like you truly have control over the actions of each character. As for the "hunter" fantasy, in the early game it feels cool to mark enemy champions and hunt them down, but in late game the fantasy usually manifests itself as simply marking the squishiest characters over and over and hoping you can kill them. This doesn't really translate to engaging gameplay for the enemy team other than "don't die or Kindred gets more damage to kill you faster next time".
In other words, Kindred is flawed in both gameplay and thematic fantasy.
Gameplay
In my opinion, the two nerfs that really hit Kindred hard were in patches 6.9 and 6.11 - namely, the nerfs to their Q's reduced cooldown and base damage, and the nerfs to E's potency. The Q nerfs killed the cadence of their early game and ruined the feel of the champion in the early levels. It also made their clear much slower. The E nerf was intended to reduce their kiting power in early trades. In order to fix Kindred's issues, their power needs to be adjusted in such a way that reduces their threat against champions in the early levels while maintaining their ability to clear camps. That way, Kindred's power curve can be much more reliable from game to game.
Riot has also expressed their intent to make crit more appealing for Kindred. The way Kindred's kit currently is, though, makes it difficult to make on-hit less desirable. So much of Kindred's power is loaded into their % current HP on-hit passive that it leaves little room to buff other aspects of their kit, let alone allowing for crit to be appealing. I think that in order to make Kindred a truly healthy Marksman jungler, the % current HP passive needs to go. Kindred players can still opt into on-hit if they choose, simply due to the nature of being a ranged champion that can safely apply on-hit, but they shouldn't be shoehorned into it, especially if Riot wants to promote them building crit instead.
Thematic Fantasy
Let's be honest. How many people on the boards do you see calling Kindred "she"? Hell, I've even seen some Rioters refer to Kindred as "she". Wolf's part in Kindred's gameplay pattern simply isn't well-realized. Their theme as a dual-entity champion is pretty watered down and Lamb's role in-game is overemphasized. Any change to Kindred should place more emphasis on Wolf's contribution to the champion's success in-game.
Also, the only real aspect of hunting in Kindred's kit is found in their passive. Marking targets for death feels cool, but there isn't much in Kindred's kit that directly supports "hunting someone down". Yes, Kindred can chain together Q's to cover distance or use their E slow to catch someone out, but those spells don't feel impactful as hunting tools. Kindred's hunter of death fantasy should be enhanced - when a champion is marked for death, they need to know that they personally are at a disadvantage to the Eternal Hunters.
So how do we go about changing Kindred's kit to fully realize their potential in both gameplay and thematic fantasy?
(Proposed kit changes are focused on the mechanics and not specific numbers.)
Passive - Mark of the Kindred
When within 2500 units of their Marked target, Kindred gains flat movement speed when moving toward them. For each mark Kindred collects, they gain permanent flat movement speed (x for monsters, y for champions).
Kindred's damage being locked up in a conditional passive makes their playstyle extremely feast or famine. I like the idea of marking targets for death, but I think that collecting marks should make it easier to apply damage, not adding damage period. This allows for more damage to be pumped into Kindred's other abilities. The removal of on-hit damage also allows their kit to be shifted to more easily accomodate crit.
The movement speed towards Marked targets also makes it more meaningful gameplay-wise to be marked by Kindred. You can't really outplay stronger autoattacks, but you can outplay Kindred's kit once she reaches you (more on that below). It also gives more options for Kindred's enemy; Kindred can get to their target faster, so it's on the enemy team to peel them off the target or get out of their range. Overall, the passive feels more like a hunt. Also, the flat movement speed reward for collecting marks is permanent to make it more appealing, but it doesn't have to be - it could be added onto the conditional movement speed toward Marked targets.
Q - Dance of Arrows
Cooldown is changed to a flat number. Damage scales with bonus attack damage and is increased against monsters. Mana cost is increased, but the cost is halved within Wolf's Frenzy zone.
These changes would make Kindred more consistent throughout the game. Q's early damage against champions would still be lower, but the AoE against monsters would be stronger, helping their clear. If they pick up early kills, then their Q damage is augmented significantly from early AD purchases. The cooldown would be consistent, regardless of whether or not Kindred is in the Wolf's Frenzy zone. To prevent them from spamming this ability outside the zone, the base mana cost is increased. They can still use it to cross terrain and navigate the map, but it can't be spammed to relentlessly pursue enemies.
W - Wolf's Frenzy
Ability is changed to a toggle effect, draining mana per second with a static cooldown upon ending the effect. Lamb gains bonus attack speed within the zone and Wolf's attacks can crit.
This change would give more agency over how Kindred players utilize some of Wolf's contribution to the kit. The extra uptime and bonus attack speed would especially help out in the early game when clearing camps. Skilled Kindred players could manipulate the extended uptime to maintain a zone between camps. And when dueling other junglers early game, if the enemy jungler forced Kindred out of the zone, it would reduce a lot of their dueling power for a significant cooldown regardless of how long the zone had been active. Late game, Wolf's crits would significantly add to Kindred's DPS when within their zone of control.
I like this ability because it feels like Lamb and Wolf are working together more than their other abilities. The name of the ability could be changed to reflect this (Frenzy of the Kindred? Hunter's Ground?)
E - Mounting Dread --> E - Maim
Ability changed to a single target skillshot nuke and the range is increased to 1250. Damage changed to missing HP from maximum HP. Slow is increased in potency and decays over a longer duration.
A Marksman having a heavy targeted slow is bad news, especially when it also does hefty maximum HP damage (note: it doesn't matter when you use the ability, it will do the same amount of damage). Mounting Dread is also guilty of the "Wolf just feels like a particle effect" issue. This ability should have strategic value beyond "use it at any time", and it should feel impactful when it lands, as if Wolf just sunk his jaws into your cowardly leg.
When Kindred casts Maim, Wolf leans back on his haunches for a moment before pouncing in the target direction. This ability would have % missing HP damage and a hefty slow, which introduces an interesting choice. "Should I use this at the beginning of a gank for the heavy slow, or should I save it for a snipe in case the enemy escapes with low health?" This also increases Wolf's contribution to the kit. His pounce would feel more responsive and powerful than his current particle effect status, since the player would literally be inputting the command for Wolf to pounce, similar to how they input the command for Lamb to vault with Q.
R - Lamb's Respite
Unchanged.
I love this ability. So much gameplay involved. No changes are needed.
And that's it. I personally feel like this would solve a lot of Kindred's game health issues and promote more interactive gameplay between them and their opponents, while also smoothing out their power curve from game to game and making them less feast or famine. I obviously could be wrong on this assumption, but that's what discussion and critique is for. :)
With rumors of upcoming work to Kindred's kit, I hope that this concept can gain some traction and hopefully make some sort of an impact on what Riot decides to do with the Eternal Hunters. I love Kindred's kit and their character and used to play them all the time last season. I would love for this champion to be in a healthier state so that I can enjoy them in Ranked once again. :) Please leave comments below, I would love to hear your thoughts on this proposed kit!
-BOOM