[Scripting Question] partner trainer who teleports at random (20.1)

class Game_Follower < Game_Event
  attr_writer :map
  def initialize(event_data)
    # Create RPG::Event to base self on
    rpg_event = RPG::Event.new(event_data.x, event_data.y)
    rpg_event.id = event_data.event_id
    rpg_event.name = event_data.event_name
    if event_data.common_event_id
      # Must setup common event list here and now
      common_event = Game_CommonEvent.new(event_data.common_event_id)
      rpg_event.pages[0].list = common_event.list
    end
    # Create self
    super(event_data.original_map_id, rpg_event, $map_factory.getMap(event_data.current_map_id))
    # Modify self
    self.character_name = event_data.character_name
    self.character_hue  = event_data.character_hue
    case event_data.direction
    when 2 then turn_down
    when 4 then turn_left
    when 6 then turn_right
    when 8 then turn_up
    end
  end
#=============================================================================

  def move_through(direction)
    old_through = @through
    @through = true
    case direction
    when 2 then move_down
    when 4 then move_left
    when 6 then move_right
    when 8 then move_up
    end
    @through = old_through
  end

  def move_fancy(direction)
    delta_x = (direction == 6) ? 1 : (direction == 4) ? -1 : 0
    delta_y = (direction == 2) ? 1 : (direction == 8) ? -1 : 0
    new_x = self.x + delta_x
    new_y = self.y + delta_y
    # Move if new position is the player's, or the new position is passable,
    # or self's current position is not passable
    if ($game_player.x == new_x && $game_player.y == new_y) ||
       location_passable?(new_x, new_y, 10 - direction) ||
       !location_passable?(self.x, self.y, direction)
      move_through(direction)
    end
  end
end

def pbStuckTile(event=nil)
  event = $game_player if !event
  return if !event
  $PokemonGlobal.stuck=true
  event.straighten
  event.calculate_bush_depth
  olddir=event.direction
  dir=olddir
  turntimes=0
  loop do
    break if turntimes>=Deep_Marsh_Tiles::MARSHTILES_TURN_TIMES
    Graphics.update
    Input.update
    pbUpdateSceneMap
    key=Input.dir4
    dir=key if key>0
    if dir!=olddir
      case dir
        when 2 then $game_player.turn_down
        when 4 then $game_player.turn_left
        when 6 then $game_player.turn_right
        when 8 then $game_player.turn_up
      end
      olddir=dir
      turntimes+=1
    end
  end
  event.center(event.x,event.y)
  event.straighten
  $PokemonGlobal.stuck=false
  $PokemonGlobal.mudfree=true
  event.jump(0,0)
  pbSEPlay(Deep_Marsh_Tiles::MARSHTILES_JUMP_SOUND)
  20.times do
    Graphics.update
    Input.update
    pbUpdateSceneMap
  end
  $PokemonGlobal.mudfree=false
end