Correct me if I’m wrong, but from my understanding, it’s only impossible for an object with mass to accelerate to the speed of light. If something was magically accelerated to above c, it wouldn’t break any rules to stay above c.
So what would happen in a collision between a slow object and something moving faster than c?
Yeah, no interaction at all is my best guess as well. Tachyons are the realm of some pretty weird shit. (And they probably don’t exist at all.) Imaginary mass and all that.