if blackhole A was sucked into blackhole B, wouldn't blackhole B be sucked into black hole A thus creating time travel
This literally made me burst out laughing, a black hole is an unmatched and complete void where in no matter exists and, being an instantaneous singularity, the concept of time is null and void. Therefore the idea that black holes would somehow consume one other is not only obscene but the idea that it would somehow mess with the time space continuum is completely inefficacious.
BTW black holes can't suck each other in that's dumb.