Tahm Kench's win rate as a support is currently only at around 45%, which makes it one of the lowest ones in the game as of now. [(according to champion.gg)](https://champion.gg/champion/TahmKench/Support)
So, since I main him, I thought about how he could be buffed without making him too strong.
I think that, when Tahm eats an allied champion, he should give them a small heal over time, and the longer they stay in his stomach, the more they get healed. Not too big of a heal, just so that, when you for example save a teammate with like 30hp left, he gets healed by maybe 90hp if he stays in Tahm's stomach for the whole two seconds, which then gives him an actual chance of escaping from the enemy. I'm not sure about the exact numbers, but definitely nothing too crazy, just a minor additional effect. Like for example 30, 50, 70, 90, 120 per ability level.
Staying longer to get more heal lets the enemies catch up, however if you leave earlier you will get healed for less. It's a high risk - high reward mechanic.
In lane phase, since you would have to 'waste' more than two seconds to get the full heal, it wouldn't be op either. However, later on in the game it would definitely help Tahm save more lives.
Let me know your thoughts :D