Rammus

the Armordillo

Tank

OK.

The build that broke the game

Ninja Tabi

Thornmail

Sunfire Cape

Randuin's Omen

Frozen Heart

Warmog's Armor

Why it worked

Defensive Ball Curl reflected damage off his armour, and Thornmail added a percentage of it on top. A marksman attacking Rammus killed himself quicker than anything else on the field — the counterplay was to stop. Powerball then carried all of that into the enemy backline from off-screen.