Tahm Kench Build Guide by ChocoChurro

The early game.

Nobody uses Glacial Augment Tahm Kench. He's underrated. YOUR OPPONENTS will understimate you. And even if they don't you'll be able of take a lot of advantage.
IMPORTANT ADVISE: only use this pick against melee champions. You'll suffer a lot and probably not gain anything against ranged top laners.
You'll take minion dematerializer to farm easier with Tahm Kench, as he has a very poor wave clear until he gets Sunfire Cape. But you won't have minion dematerializer until you're lvl 3 or 4, so one you get lvl 2 you'll have to all-in the enemy toplaner, hitting your Q. If you did, you'll just AA him until you can devour him,as he won't be able to escape because of the Q slow, the Glacial Augment and your bonus attack speed, and vomit him towards your side of the lane. Then, repeat until you kill him and then you'll have your mind on farming until he comes back.
You should be one lvl above him. If you don't but you are at high HP, just all-in him again like before, but you should have your E now if the match-up gets a little difficult.
If you did well and you could farm decently, you'll fastly have enough gold for Bami's Cinder. If you killed the toplaner at least two times, you should go back to the base to buy Bami's Cinder and you'll farm a lot easier as having even more damage in trades against your enemy toplaner.

You should already have Swiftness Boots, so enemies without movement speed bonus shouldn't be able to escape from you if you hit your Qs. And you'll have Sunfire Cape to damage them even more with just being side-to-side to you because of the slows.
You may want to have Spirit Vesage to have faster healing from your E's passive, and Gargoyle Plate to increase your tankyness. But you also can build Deadman's Plate before Gargoyle to hit even more from your AA, which in fact for being from a tank support, they have a pretty decent both physical and magic damage.
Oh, and you should be able to even steal kills.

Ok, this is it. You are one of the most tanky **********ers in the game, you CC a lot, you can roam to basically the entire map WITH A TEAMMATE, and in the frontlane even if they CC you you'll be unstoppable.
With Gargoyle Plate active's skill and Warmog you'll be basically immortal and able to get back to fights very easily and even at this point of the game, still able to get kills, specially against squishy champions.
You're the game.