Ok. Before anyone call shenanigans on the complex's size. Note that Takeshi had 50 years to plan and secure the necessary infrastructure for what he wanted to do.

If I remember correctly, 50 years ago Takeshi was invited by Captain Taiki to reinforce wards on Hannibal's cell? So whatever talk about masks, and his subsequent discovery of the artifact would have allowed him to kick start plans and build up whatever he needed.