Full Crit Tahm Kench Build

General

1. You go Full Crit.
2. You go in and play around Hail of Blades to burst enemies.
3. You back away and wait for Hail of Blades. Repeat.
4. This build works best if enemy team has squishy champions. If you are against a lot off-tanks/bruisers, this might not be best build. You can make it work, however, by rushing Lord Dominik's Regards.

Champion

1. Your usual combo is going to be: three autos with Hail of Blades, then stun with Q. Then keep auto attacking.

General

1. This build shines with 100% crit. You will instakill squishes. Until that, it might be challenging to 100-0 anyone. Look for opportunities to go in and score kills. Also focus on farming minions if possible (to scale faster).
2. Wait for your moment to go for a kill. You have a big burst thanks to Full Crit and Hail of Blades, but you are squishy. And outside of Hail of Blades procs (especially early game) you don't have much damage.
3. Snowball / Mark is an essential cooldown for this build. Do not waste it or even wait to hit the enemy at point-blank range to ensure hit (so you follow them, if they Flash).
4. Enemy team might not check your items right away, you could use that for your advantage to nuke unsuspected enemy.
5. After they checked your items and noticed that you have damage and are squishy, they are going to target you in fights. Be careful, after early game probably you need to modify your playstyle and stay back and wait for a good moment to join fights.
6. If they have tons of CC, get Mercury's Treads, Edge of Night or even Mercurial Scimitar to counter that.
7. If you are not doing well, or an enemy team is slightly ahead, you can adapt and buy tank items. Worst case scenario, you can sell everything late game and 'respec' into full tank.

Champion

1. Combo #1: Q + R combo. If you have three stacks of your An Acquired Taste (Passive) on your target, you can eat them from a distance. During Tongue Lash (Q) animation use Devour (R).
2. You can cancel your Abyssal Dive (W) with Flash in case of emergency.
3. If you know you will get alive, don't use Thick Skin (E). Let it heal you instead.
4. Want to hit Abyssal Dive (W)? Face the other direction to mislead the enemy.
5. Hit Tongue Lash (Q) first, then use Abyssal Dive right away for certain hit.
6. Just ate enemy player? Don't spit him out immediately. Wait for your cooldown, your allies and their cooldowns as well. Ping them if needed.

Riot

1. Your most important function as a support is to keep fragile allies safe. Keep Devour's range and cooldown in mind and position accordingly!
2. Consider carefully when to use Thick Skin's active. Sometimes shielding early to avoid further damage is good, but sometimes the healing is more beneficial.