The full video starts with X on a highway shooting two maverick bee bots.
It cuts to him fighting Launch Octopus.
Then you see X running from a burst of flame in an underground cave. He jumps out to the surface where he sees Vile with his gun ready.
Right before Vile shoots, he gets sliced in two by Zero. X then runs towards Sigma\'s base. Two mavericks (Forgot who they were) chase after X, but Zero wards them back with his saber.
As X is running, the door to the base starts to close. X switches to his X1 Armor and dives under the door. He sees X1 Sigma. He dives under a pillar, which Sigma slices.
X transforms into his X2 armor. Sigma goes into his X2 mode. X fires, Sigma deflects it. X fires again, Sigma get s vaporized. The scene pans out to Dr. Doppler holding a ball of energy watching X, as Doppler is surrounded by all the Mavericks.
So, yes, it is X3.