Ah, Li Li... she's an odd one as her biggest strength is how easy she is to use.
Too easy probably, yet she is too weak at higher levels of play. So I decide to weaken her easy-to-use Q in exchange for some playmaking tools and go from there.

The baseline Let's Go is the most obvious (even if at double cooldown, this cooldown can still be reduced back to 40 seconds with the newly improved level 7 talent), but also the Baseline addition of Hindering Winds, removing this talent as it is pretty much a forced pick unless you buff the other talents to ridiculous levels
A 25-30% slow is however too much, so I decided to put part of this slow behind a quest.

But at level 1 her talents got a major improvement too, making this a far more important talent choice than it has ever been.

At level 4 I just moved Free Drinks into the empty slot, as it no longer has a place on the level 1 tier.

At Level 7, there is a Cleanse improvement in Gotta Go faster and a buff to the Serpent talent, hopefully making this viable.

For her Heroics, I think they are mostly fine. Jug is great as it is and I decided not to change it, but the Dragon is a little on the weak side, so I gave it a 13% damage buff and a significant heal reduction. Oh, and a Try Again button if you fail.

At higher tiers I don't think Li Li needs any changes (as level 13 is fine and the weaker talents on 16 and 20 benefit from the changes to Li Li's other tiers. The only change I really made is giving Mistweaver a 10% buff.

Original posted: 4 June 2018

EDIT 17-07-2018: Added some more interactivity in her gameplay with a re-tooling of her Q; I reduced its healing by another ~6% but also added interactivity with Cloud Serpent.
You can either use your level 1 Q talent to guarantee this synergy, or you just have to position yourself correctly to hit this target!
Also her talent tree received a few minor changes.
The Level 4 Serpent talent now also increases the damage the serpent deals to Blinded targets. Li Li will struggle to proc this on her own, but that's what teammates are for.
Also a nerf to the level 7 Cleanse talent, as I removed the duration increase. Cleanse is very powerful and I do feel that this talent would be a slightly too obvious pick with how powerful Cleanse tends to be. Lastly, on level 13, Gale Force' damage increase also now affects all targets, not just Heroes, mostly because I feel this is more intuitive, especially with the level 4 Serpent Sidekick buff.

EDIT 28-09-2018
Reworked her 13 tier. Gale Force was a talent I was not happy with (even when I made my previous update - I just did not know how to deal with it yet) because it is a mandatory pick whenever Li Li is drafted, because the reasons to draft Li Li in the first place heavily overlap with the reasons to pick Gale Force. As such, I decided to reinclude the old Kung Fu Hustle into Li Li's kit to replace Gale Force entirely, though it does increase the damage versus Blinded targets all the same. I also made Surging Winds more intuitive, removing its condition and making it a very solid talent of its own. Mass Vortex is fine as it is, even if it feels like a QM-orientated talent.
I also reduced the number of stacks needed for her level 1 talent - it's hard enough to stack Cassia's Plate of the Whale under most circumstances and this quest is even more conditional, even if you have the quest available before the level 1 midlane brawl, so I cut the number in half. Not every match has a Tracer, after all!

EDIT: 09-10-2018 Baseline quest reworked into a standard Globe gathering quest. The quest of stacking on prevented AAs seems fine, even if heroes like Tracer stack it really quickly or it can be prevented (just stop AA'ing for a bit), but the latter really only means that it gets value from bad players, while I like it to reward playing well. This also allowed me to make Let's Go scale at the normal 4% while still becoming stronger into the lategame due to the permanently stacking quest.
Mistweaver also nerfed from 181 to its original value of 165. As for the 10-10-2018 Patch, I don't think this stronger incarnation of Li Li needs the HP buff, and the Cloud Serpent cooldown is already set to 10 seconds (odd, I don't remember changing that number?). Jugs nerf is included, however.