slay: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/sbin/slay - from package: slay

You may install the required package with command apt-get install {package}

Error in other languages:
slay: bevel nie gevind nie
slay: comandă negăsită
slay: comando não encontrado
slay: commande introuvable
slay: command not found
slay: käsku ei ole
slay: không tìm thấy lệnh
slay: komanda nerasta
slay: Kommando nicht gefunden.
slay: kommandot finns inte
slay: komut yok
slay: nie znaleziono polecenia
slay: níor aimsíodh an t-ordú
slay: no se encontró la orden
slay: no s'ha trobat l'ordre
slay: opdracht niet gevonden
slay: parancs nem található
slay: perintah tidak ditemukan
slay: príkaz nenájdený
slay: příkaz nenalezen
slay: команда не найдена
slay: командата не е открита
slay: 命令找不到
slay: コマンドが見つかりません