In an all-out WAR including all Legendary Pokemon, which 2 would be the last ones standing? Who would win the one victorious? Discuss why you selected your choices.
Wow, such a war, it'd be amazing, I'd wanna see that so much ! Well, I won't count Arceus. Because it's God. And, being God, it's supposed to have all the powers, to be the ultimate being so the war wouldn't be interesting with it.
In that case, I think the two last ones standing would be Mewtwo and Rayquaza. Mewtwo would have resisted protecting itself as it shows it can in the first movie, and its psychic attack can overcome even the most powerful fire/water/whatever you want attacks. It would reflect its opponent's own attack against them. And I imagine a long battle between Rayquaza and Deoxys (like in the 7th movie), while every one else fight together, and when Rayquaza manages to beat Deoxys, it only remains Mewtwo. Then Mewtwo wins.