Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
This is the final anti-tank build. It's a bit slow but testing it lot of times, i found the best way not to be too weak in the beginning. With this build you should go in lane with Kayle or Taric, to let you exp enough without risking, or with Nasus or other slowers that maximize the effect of your skills.
Your bio-arcane barrage is the main skill. If you have it, you are deadly, if you don't, you are useless. Keep it charged for when you are sure you can kill: harassing enemies with your artillery.
With this build you have enough armor pen and AS to kill any tank but you could need to modify the build according to the other team. Switch Black Cleaver with a Bloodthirster: with 3 lifesteal items, your survivability raise while sacrificing your armor pen.
Frozen Mallet in late game will help you a lot in team fights because you can slow the enemies attacking and will give you enough HP to survive till you can shoot out all your crazy damage and regen your hp.