Many turns or "I will fight you!"

[Deebiia]

 2 {Iron Myr}, 2 {Palladium Myr},  {Aggravated Assault},  {Medomai the Ageless}(Optional)

With more myr creatures it could be infinite mana I believe.

[Spikepit]

Forget Medomai, his text says he can't attack in extra turns, but adding 2x {Myr Galvanizer} and you're in business for infinite!

[Minecraft1]

{Fortress Cyclops} gets more powerful each time

[MarduArrow]

{Fortress Cyclops} gets more powerful each time

Or even better  {Tajic, Blade of the Legion}

[Mlerner12]

[Wackaman9001]

So long as they don't kill medomai you can kill them that turn, but really any flier will do

[Anoobass]

Even then, {Aggravated Assault} gives an extra combat phase, Medomai can still attack, she is only not allowed to attack on extra TURNS.  So if your playing multiplayer widle out everyone you can and then just use all of your extra turns that you tacked up with Medomai to kill the last few.

[Double-O-Scotch]

Throw in {seize the day}...

[Steerpike]

Throw in {seize the day}...

What a girthy blade

[Wackaman9001]

I love {Bear Umbra} on a {Hellkite Charger}, so many rage quits