RenameTvSeries.ps1

function Rename-TVEpisodes{
[CmdletBinding(SupportsShouldProcess)]
Param(
   [string]$Name,
   [int]$Season = 1)
process{
$seasonFolders = dir -Directory
$seasonFolders | %{
    $seasonFolderName = $PSItem.FullName
    $seasonStr = "$($Season)".PadLeft(2,"0");
    $Season++;
    $index = 0;
    if($pscmdlet.ShouldProcess($Name))
    {
        gci $_.FullName -File -Filter *.mkv | % {
               $index++;
               $str = "$($index)".PadLeft(2,"0");
               mv -LiteralPath $PSItem.FullName
                  -Destination "$($seasonFolderName)/$($Name) S$($seasonStr)E$($str)$($PSItem.Extension)" -Force
               }
    }
    else
    {
        gci $_.FullName -File -Filter *.mkv | % {
               $index++;
               $str = "$($index)".PadLeft(2,"0");
               mv -LiteralPath $PSItem.FullName
                  -Destination "$($seasonFolderName)/$($Name) S$($seasonStr)E$($str)$($PSItem.Extension)" -Force -WhatIf
               }
    }
}
}
}

# Animes for example usually use a continous number for episodes, which is hard for media platforms to crunch
# In my experience most of these series have season folders but still use the global numbering system.
# this script will traverse in to all subfolders, treating them as a season starting with the $Season param number
# It will then rename all episodes to the more standard "{Name} S{Season}E{EpisodeIndex}" format

#Given an example
# Naruto Shippuden S1
# > Naruto Shippuden - 1.mkv
# > ...
# ...
# Naruto Shippuden S21
# > Naruto Shippuden - 480.mkv
# > Naruto Shippuden - 481.mkv
# > Naruto Shippuden - 482.mkv
# > Naruto Shippuden - 483.mkv
# > ...

# Rename-TVEpisodes "Naruto Shippuden"
# Will result in the following folder structure
# Naruto Shippuden S1
# > Naruto Shippuden S01E01.mkv
# > ...
# ...
# Naruto Shippuden S21
# > Naruto Shippuden S21E01.mkv
# > Naruto Shippuden S21E02.mkv
# > Naruto Shippuden S21E03.mkv
# > Naruto Shippuden S21E04.mkv
# > ...