Buster Machine III from Gunbuster is 800 km sized construct, a black hole bomb designed to take out as much Space Monsters as possible in the Milky Way galaxy.
3000 slave units are stationed lightyears away to boost BMIII's 'yield'. In other words, BMIII also serves as main fuse to detonate other 3000 slave units.
Milky Way's size
In pixels = 657 px In lyrs = 100000 lyrs
BMIII's Black Hole size
In pixels = 418 px In lyrs = 63622.53 = 101880099723317000 solarmass = 5,80003E+58 J = 28 times the baseline 4-A Multi Solar System
Note : I used www.omnicalculator.com/physics/schwarzschild-radius to find out the solar mass of a given radius