**Preface** - I'm an unabashed Tahm Kench lover. I have 900k mastery points on him and I'm consistently active in the Kench Subreddit and Discord discussing how/why Tahm is either over-tuned or under-tuned.
Riot, Tahm Kench will literally be unplayable. An 11% nerf to HP at level 1, for a 1% gain to HP at level 18? 11% is 2 auto attacks worth of HP at level 1 for champions with _**zero**_ items. 1% gain is not even a quarter of an auto-attack at level 18 from anything other than Karthus, in most instances it's less than a quarter of the damage a 6 item ADC would do! Tahm Kench will literally never be picked in solo queue and this _**still**_ won't solve his pick/ban status in Competitive play.
You want Kench to be balanced and see play in solo queue while limiting his impact on Competitive? Nerf the cooldown on his ultimate -- make it 180/160/140 seconds at rank 1/2/3, while increasing the range by 1000 at all ranks. Revert the CD to 6 seconds on Q. This will balance Tahm around his ability to out-macro (one of the primary reasons he's picked in competitive). Either that or re-work his ultimate completely.
Kench relies heavily on HP, more so than Braum -- who has a dash, a wall/shield, and a hard engage ultimate, and a Q that allows allies to apply towards stacks and stun -- Kench has a sometimes reliable ultimate that falls off significantly in late game play, no dash and no hard CC. Kench is pick ban for a single ability in pro play with a 47% winrate in soloqueue.
You've already doubled the CD on W when used on allies, and it's broken half the time (where if you use it on something other than an ally that dies mid-animation, it still gets hit with the FULL cooldown). The base HP nerf will affect Tahm much harder than it will affect Braum. Tahm cannot E-shield at 50 HP remaining and block 600 damage. Braum can Wall at 50 HP remaining and block 600 damage for himself as well as an ally. Tahm has no dash. Braum can dash. Tahm has no combat ultimate. Braum has a combat ultimate.
You are comparing a 50% win rate Braum (AFTER his baseline nerf from last patch which you _**directly reference as a comparison for the reason to nerf Tahm this patch**_) to a 47% win rate Tahm Kench -- _**Before this nerf even goes into effect!**_
Riot you are literally going to make Tahm Kench unplayable after this nerf. He's already the _**LOWEST**_ win rate support for ALL regions in Platinum+ Elo, and you are _**NERFING HIM AGAIN**_.
> Tahm Kench
> Base HP down; HP per level up.
> Similar to Braum last patch, we’re looking to drain some of Tahm Kench’s baseline sturdiness. Reducing Tahm’s base HP should make him rely more on his defensive tools to find success in lane, while increasing his HP gained per level will make it slightly easier for him to wade into the enemy team late game.
> Base Stats
> HEALTH 610 ⇒ 540
> HEALTH GROWTH 95 ⇒ 102
> W - Devour
> BUGFIX Allies Tahm Kench has devoured will no longer sometimes be targetable when first swallowed.