Tahm Kench, AP Attack Speed? or Tank?

Start out building tanky with a little ap. Get the hang of him first before trying other things.

try using your brain to think of your own builds. it also helps with learning the game and becoming a smarter person in general. also, he scales on everything so it basically doesnt matter. can buy five infinity edges on him and be good.

It's unlikely you'll build enough dmg to outscale the 6% bonus hp from ultimate and 32% enemies max hp from your regurgitate. So that gonna be your main source of damage. Add on top of that your grey hp bar that scale from hp and you have your answer.

Tahm is a tank with very large amount of hp. .

i'm tempted to round it with hp5. . Because with all that regen from the grey health, you'll be close to outsustain the majority of damage taken. Regeneration tend to scale dramaticaly well once you reach that point. To be specific, if i take 100 hp of dmg but regen 10hp, adding another 10 hp. will make me survive 10% longer. however.. if i already regen 80 hp of it, i'll double my life span, and then 10 more hp will turn me invisible !