The change in History and Present

one day earth climate become unstable
extremely hot places become cold
and coldest mountain started to melt
exact that day sky Chang it's colour every single big land was sharing different colors of sky and then boom a sound resonate in earth atmosphere creature that were only myth appear dragon Giant snake Phoenix giant bird insect all fell from the sky and massacre started human try to fight back but it was for nothing the entire earth lose its original specis exact that moment sky started to become clear a giant portal can be seen from that portal voices were resonating on entire earth theywere discussing about earth after long discussion a word resonate in earth
that word Chang entire structure and history of earth that word was
reset yeah reset after reseting exact same moment repeated them selves but this time something was diffrent when sky colour Chang in entire earth all govt make a annoucemmant that it was plan scientist already know about it and after that tower appear in earth and dungeons started to appear some people disappear and some awaken ability or power
but it was not the end into tower those who become climber receive the biggest shock ever after clearing some floor they loss
controls of there ability and when they come out side the tower they receive another shock world they knew was changed
what change bring these strange tower
how did govt know about that
if govt know about that why did they not stop this
but it was not the end last survived of tower when come out side the tower
they lose all the hope
what govt did with them
why didn't public know about climber return
and what was the Oirigin of tower and dungeon