You don't pull Susano'o Itachi. You slowly get his frags, the same method as Kage treasures.
wait really!? Here I was thinking I'd just get lucky pulls for his frags here and there. Well if I can't pull him, don't need sasuke or Ay or really danzo, then I guess I'm either saving for jinchuriki or spending on tendo to get the last two pains I'm missing (excluding the 4 frags of tendo I need...... OASIS.....).