shao, suygetsu, redgar, nats, something, and chronicle are all russian citizens, demon1 is a US citizen. so that's how the process was faster for demon1
and I don't think something ever played on LAN in japan, I think he was playing from vlaivostok (eastern Russia). EDIT: incorrect
the process for the above mentioned russian players probably took just as long, but since they were signed during the off-season they had a lot more time to get their paperwork taken care of.
Something was barely signed in late march, so there's really only 3 months of leeway for him
Welcome to the world of immigration beauracracy, this shit usually takes months. Once a work visa expires or you lose the work that you justified under that visa, the only thing that becomes easier is your odds of getting another visa accepted again in the future (it can be rejected), but it will still take just as long.