多分これが一番早いと思います

lvup.js

// spidermonkey
abs = function (x){ return (x ^ (x >> 31)) - (x >> 31);}
repeat = function (s,n){ return new Array(++n).join(s);}
var w = 20
for(var i = 0;i<=100;i+=2)
{
  for(var j = 0;j<w*2;++j)
  {
    print("呉x"+i);
    var a = repeat(" ",abs(j-w));
    var b = repeat(" ",w-abs(j-w));
    for(var k = 0;k<w/4;k++)
    {
      if(k==~~(abs(j-w)/4)){
        print(repeat(" ",w)+"呉");
      }else{
        print();
      } 
    }
    print(a+"⊖"+b+b+"⊖");
    sleep(1/60);
  }
}

[http://upload.aki017.info/raw/2013-05-03-095221.gif]