What Does Getsuga Tenshou Mean In English Ichigo s final getsuga tenshou the ultimate deus ex machina in bleach that has no explanation or does it

It is half explained at the end of the fake karakura town arc and fully isshin told ichigo while he was trying to learn the final getsuga tensho my zanpakuto didn t let me learn how to use this means isshin no longer has to hold anyone s hollow back so his soul reaper powers return to him