I really wish for Klei to not fall into their own trap again, and would rather they avoid making these skill trees without any consideration for why some characters have such a low play rate and are generally a nuisance to play due to how restrictive and inaccessible their kit is. Characters like wurt and warly are very good examples. Even though wurts already had her skill tree, it didn't really fix any of her issues that cause her play rate to be so low, not to say that they are incapable of fixing characters, as they demonstrated they very well could with the previous skill tree, where they added some minor but useful QoL changes and straight-up buffed the damage output of Walter's base kit, turning him into a pretty decent character even without his new skills. Thus, I hope for Klei to not only implement new stuff with warly's skill tree, but also take a look back at his base kit and maybe fix or add some skills that could boost his early game, and have his upsides be more rewarding—all the while making his new skills interact with his base ones for more interesting gameplay. Since I think it really sucks for warly to have one of the worst downsides and have his kit be restricted to some difficult ingredients or tedious crop farming, essentially turning him into a wilson with more downsides than upsides in the early game.
With that said here are some of my suggestions.
Chef's Grace I
Any numerical buffs gained from food (all of Warly's spices, jelly, and a new speed drink) are now 10-50% more effective for Warly, depending on the number of unique recipes Warly has eaten in the past 3 days. For each unique food Warly has eaten in the past 2-3 days, he gains +10%.
Chef's Grace II
Stat-regenerative effects gained from food are now also increased by 10-50% (regenerative ticking effects, not flat healing gained from eating food; includes new drinks, Forget-Me-Lot tea, and jellybeans).
Scent of Home
All effects, numerical buffs, and stat-regenerative effects Warly has activated through consuming food are now shared with nearby allies unless they walk too far from warly. Special effects like hot dragon salad, fish cordon and his other unique food dishes will apply to nearby allies (although probably with the exception of nightmare pie since I think it could cause more harm than good in the wrong hands). These effects will remain on nearby allies unless they walk away from Warly. Numerical buffs and regenerative effects are 50% less effective and will become 10% less effective for each additional player near Warly. For example, if there is 1 player near Warly, they'd get 50% of his numerical buffs and regen effects. If there are 2 players, each would receive 40%, and this continues until a cap of 30%. Players can still grant themselves the buffs by eating the same food as Warly, and these will stack with Warly's AOE buff.
This might sound overpowered, but it isn’t as insane as it sounds. For example, chili flakes grant a 20% damage boost. This value increases by 10-50% (depending on Chef's Grace I), giving Warly a 22-30% damage boost. His ally would then receive an 11-15% damage boost (50% of warly's numerical buffs), which might sound like a lot, but these values decrease based on the number of allies benefiting from Warly’s buff and only persist when near warly as a trade off. If the ally eats the chili flakes as well, their damage would increase by 20%, so in total they would have a 31-35% damage increase with warlys aoe buff assuming that there is only 1 ally near warly and warly has eaten the chili flakes as well.
To complement these skills (or simply give him something new), Warly could have a drink crafting station that will use early game accesible ingredients where he can make the following drinks: a early game accessible movement speed drink (energy drink or coffee? yea not sure here), sanity regen drink, and health regen drink. These would tie perfectly into his previously mentioned skills.
All of the above skills would make his kit much cheaper and more accessible since he would only need to make food for himself to impact his team. If warly however goes through the extra time and trouble to cook for the entire team instead, it would allow for his food buffs to be more effective than if he were to only cook for himself.
This also gives players an incentive to use him as an actual character, instead of just mass farming ingredients and cooking his exclusive food, only to switch back to another character.
As for scripting, I’m sure the team can manage it, especially since they were able to pull off all of the planar stuff.
Shadow and Lunar Affinity
For his Shadow and Lunar affinity, I would suggest granting him spices that provide planar defense and attack, along with special effects (tied to Chef's Grace and Scent of Home skills) depending on the affinity. Having this be locked behind rifts shouldn’t be a huge problem, as long as Klei focuses on adding stuff to make him a little more engaging in the early game, instead of locking recipes behind difficult crop farming, have their effects only be useful in specific seasons or expensive ingredients.
Some filler/utility skills could be something like:
Certified Butcher/Agriculturist
50%chance for an additional item drop from enemies or crops he harvests/hammers. This only works on items that are crockpot ingredients (volt horn, n-fuel, meat, etc.).
Mighty pepper
Warly now starts off with a pepper in his inventory
Food Stash
Gives chef’s pouch more space and effectiveness.
Spice expert
+1 spices gained from crafting them.
Some of these skills might not really fit the aesthetic of the game or might be too strong, but I definitely think that some of them help fix his character—making him less of a late-game-only switch character and rewarding you when you know how to deal with his downsides, all the while making his kit more accessible. Warly might be a tough nut to crack when it comes to implementing a skill tree for him compared to other characters, but that shouldn't mean he gets a lazy one. It would be wise to think outside the box for his tree, so I think granting him some skills outside of his chef gimmick would probably be for the best. The skill tree should aim to fix issues with his base kit while also adding more flavor to his core gameplay and mechanics -all the while strengthening him so he can keep up with other characters. I think granting him a cheap, early-game-accessible, speed-granting consumable would make him significantly stronger than he is now—or honestly, I believe just having him start off with a pepper in his inventory (as a base kit update) would make him much more consistent and early-game-friendly.
Guille did an exceptional job explaining Warly's issues, core gameplay and how to fix Warly's kit.