I am not sure what you're trying to do here, exactly... The point of that old thread was to see how close we could get to creating Pun-Pun within the core rules. Pun-Pun is basically a creature that has every ability in the D&D universe, along with infinite hit points/dice, infinite ability scores, etc. The main mechanism of doing this was using an ability from the Serpent Kingdoms book. To even try and reproduce this in the core rules, you pretty much have to be a 17th+ level wizard, likely with a high level druid/heirophant ally.
However, it is possible to "layer" creature abilities via combinations of the Similacrum and Shapechange spells, and other methods of changing shape (Wild Shape, Polymorph, etc). The core mechanism was to Shapechange your familiar into a useful creature, then make a Similacrum of that. The Similacrum would keep all traits of the original, including the things derived from being your familiar (including Share Spells, etc). You then Shapechange this familiar-similacrum into a new creature, and make a Similacrum of it. This 2nd generation now has the combined abilities of both the first two Shapechange forms. You basically keep going, using other methods of gaining abilities as needed (Wild Shape for "natural" abilities, IIRC), until you wind up with something with every ability in the game. I think there were some methods of ability score inflation also, but I don't remember how (or if) that worked.
This is all going from memory, so I might be off a bit on the details, but I was part of the original thread.