Soon after the forces in new york were wiped out a Garganta ripped open In Bogata and a powerful Vasto lorde Stepped out into the city. Smiling, Sen unleashed his power, a massive beacon of Reiatsu that instantly crushed some of the weaker hollows. It served to get all of their attention though.
Ignoring the weakling Arrancar shouting orders for now Sen roared a command of his own to the rabble of hollow. "Feel this energy you mindless worms! Why don't come and take a bite of true power!" Laughing madly he charged as the hollow turned and attacked him, disobaying the arrancar to get at Sen. A single bit of a Vasto Lorde might increase them to something of worth.
The Vasto Lorde rushed right into the group, tearing limbs from bodies and crushing skulls. The hollow flowed around him and attacked but nothing landed. He was to fast, and tearing through them like they were made of wet paper. Sen let them swarm on him, and then as one landed his jaw on Sen's fist that was protected by dark energy, the Vasto Lorde laughed, and unleashed his Spire of destruction. The blast of energy expanded 50ft out from him, and 100ft into the air, easily annihilating all of the hollow surrounding him.
What was left was Sen with a smug look on his face, a few charred limbs and the three arrancar. There was a few straggler in the area too, but after witnessing the deaths of so many hollow, and the destruction of a small area of the city, they fleed into hueco mundo. Sen looked at the Arrancar and singled out the weakest. In a blast of sound he was 10 feet from the weak Gillian arrancar, and launched a dark red spear of energy that would punch right through some of the strongest hierro if it hit. Then, dead or alive he shot a volley of weaker Javalins at all of the arrancar.
Once he killed theses 3 he could kill the rest of their army that was still causing trouble in the distance.