Something

alias block { 
  notice $1 you have been blocked
  set %blocked $+ $address($1,2) yes
 }
on *:open:*:*:{
  if ($($+(%,blocked,$address($nick,2)),2)) {
    msg #123456 i got here
    notice $nick Wtf u on.. u blocked lmfao msg closed stfu plz 
  close -m $nick 
  }
}
alias unblock { 
  notice $1 you have been unblocked
  unset %blocked [ $+ [ $address($1,2) ] ]
}