This will make sure that it's proper UTF-8:

#!/usr/bin/perl -slw

use strict;
use warnings;
use Encoding::FixLatin qw(fix_latin);

my $mixed_string = "L\x{e9}on L\xc3\xa9on";
my $utf8_string = fix_latin($mixed_string);
binmode STDOUT, ':encoding(UTF-8)';
print $utf8_string;
[download]