You don't know what you are doing
Why are you nerfing the only thing about tahm kench that makes him a support really? why are you not addressing the real problem which is the gross amount of damage he does with 30% magic health damage on his devour why do you choose not to do the right thing no one ever said anything about his movement speed no one ever said anything about him saving an ally being an issue its a built in part of his kit that makes him a viable support I have to ask what are you doing?
I'm just saying Tahm does a lot of dmg, basically has 2 lives, and has the utility of thresh.