Round 1: They are hunting each other in Tokyo.
Weapons and gears: Ezio has the Armor of Altair, Hidden and Hook Blades, Metal Cestus, Hidden gun with 10 rounds, Channeled Cinquedea, Sword of Altair, Crossbow with 20 bolts, 20 Throwing Knives and 5 Smoke Bombs.
47 has his Suit, Fiber Wires, Meat Cleaver, Silverballers with 35 rounds and 5 Smoke Grenades.
They are allowed to obtain or steal weapons and items in the field.
Round 2: Sword duel inside Sistine Chapel from AC2.
Ezio has the Sword of Altair and 47 has two swords that was used in the 2007's Hitman movie.
Final Round: H2H on the same ring 47 killed Sanchez.