Celldweller - I Believe You 

All rights go to their original owners.
This is where the crossover truly takes off, we have Neo meeting up with Motoko Kusanagi in the beginning, having a conversation in a private building until some mysterious figure comes knocking (who is later revealed to be Smith.)
This attracts the attention of the agents to which Neo has no choice but to fight, the agents appeared to have teamed up with the Merovingian as well to try and keep this multiversal crossing from happening.
Although they are targetting the wrong person if they wish to do this. Neo flies around to try and find answers while Alucard awaits his next opponent.
More will be revealed in Frozen.
All rights go to Madhouse, Warner Bros, Production I.G., Masamune Shirow, The Whachowski Siblings, and Kouta Hirano. Please support the official release, thank you!