@Animity, here is the modified, stripped-down version of DarthReven's script and can now mimic more than one person. All you do is right click and add users you want to imitate, as well as remove users you don't want to imitate anymore:

menu * {
  -
  Add $1 to Mimicry {
    if ($1 isin %m.nick) { 
      echo -a * $1 is ALREADY added! 
    }
    elseif ($1 != $me) { 
      set %m.nick $addtok(%m.nick,$1,32)
      echo -a * Mimicing $1 added!
    }
    else { echo -a * You can't mimic yourself! }
  }
  Remove $1 from Mimicing {
    if ($1 !isin %m.nick) { 
      echo -a * $1 is ALREADY removed! 
    }
    else {
      set %m.nick $remtok(%m.nick,$1,1,32)
      echo -a * Mimicing $1 has been removed!
    }
  }
}
on *:text:*:#:if ($istok(%m.nick,$nick,32)) { .msg $chan $1- }
on *:action:*:#:if ($istok(%m.nick,$nick,32)) { .describe $chan $1- }

Note: I didn't include the part, nick and quit event.