What is the need you have to reset variables? You could use local for your package variables (since reset only works for package variables, not lexicals) and put the code that changes $var in a block. You could also use lexicals and use my;

our $var = 42;
our $vvv = 'abc';
{
  local $var = 500;
  print "$var $vvv\n";
}
print "$var $vvv\n";
[download]

or

my $var = 42;
my $vvv = 'abc';
{
  my $var = 500;
  print "$var $vvv\n";
}
print "$var $vvv\n";
[download]