Leviathanthe Crushing Tide is... the best champion ever.
Leviathan, the Crushing Tide
Innate:Leviathan gains Momentum when moving in the same direction, up to a maximum, which grants bonus movement speed. Whenever he performs a sharp turn or comes to a halt, he expends his current Momentum to send a watery duplicate of himself continuing forward with his previous movement. Enemies hit take magic damage.
Active:Leviathan pirouettes, slashing at nearby enemies with his tail. Tail Slash can be used while moving and the radius of Tail Slash scales with Leviathan's current Momentum.
Active:Leviathan rapidly paths to the target section of trail, dealing substantial damage to enemies he passes through.