Heres the issue you are refering to kamui as a black hole type tech it is more of a wormhole. A black hole is a collection of highly condenced matter so condenced that the strings refered to by M theory become intertwined creating matter unlike any other. That matter has so much mass with such little area that the gravity equation comes up with a rediculous force of gravity inside a specific radius. The more mass the larger the radius of the singularity, point at which light cannot escape. Kamui however is more like a wormhole, a bending of spacetime to allow for an object to travel a distance faster than light. Since the speed of light is constant spacetime bends in order to accomidate objects reaching a destination quicker than lightl, well theoretically. You can think of a wormhole like bending a map so that NY touches CA with minimal distance inbetween. Wormholes work by accesing other dimensions, that is what kamui is like. The real issue in this match up is the fact that gravity is the only multidimensional force i have also made a thread on this topic. There are 4 natural forces weak nuclear, strong nuclear, electromagnetic, and gravity. Each of these forces is a product of subatomic particles, muuons, gravitrons, nutreno's etc. Gravity is the only one of the fundamental forces that acts on more than our three, arguably 4 dimensions. Gravitrons are the only subatomic particle that is a closed "string" (referencing string/M theory) as such it is not bound to the membrain that created our universe (again referencing M theory) and is therefor free to affect other dimensions, being such a force theoretically any sort of gravity attack could reach the kamui dimension as gravity is not bound to the dimensions of our universe. aaaaand done.