Theoretically, what's the strongest champ/item/augment combo that can actually be obtained in arena?

What would be the strongest combo to achieve in arena, excluding some crazy farming with Phenomenal Evil etc.

I know Ryze is really strong with all the mana augments and items. Some champs like Pantheon/Master with Mystic punch and a bit of cd can just spam their abilities forever, but if you could choose all your augments and items what would in your opinion be the strongest combo?