I donÃ¢â‚¬â„¢t usually comment on these sorts of things, but FMA has been my jam for the better part of 15 years now, so you better believe IÃ¢â‚¬â„¢m gonna jump on this like Gluttony on a burger. ThereÃ¢â‚¬â„¢s several issues in this theory that throw the calculations way off.\n\nFirst of all, the inclusion of the Seven Heavenly Virtues. First of all, the Virtues donÃ¢â‚¬â„¢t appear until Aurelius Clemens PrudentiusÃ¢â‚¬â„¢ poem Psychomachia, written around the 5th Century AD, while the Seven Deadly Sins as we know them first appear in the 4th Century through the writings of Evagrius Ponticus. (Thanks Wikipedia!) With a full 100 years between the two, itÃ¢â‚¬â„¢s pretty safe to say that these are not equivalent parts of the soul. Of course, all of that is a moot point since Hiromu Arakawa herself has said that Christianity does not exist in the world of FMA, so including the Virtues at all is a no-go from day one. With that, the calculation of the average number of souls per Homunculi should be doubled. This is of course assuming that each Homunculi has the same number of souls. \n\nSecond, the calculation of how many souls it takes to regenerate Lust during the fight against Mustang has two MAJOR assumptions that completely ruin the theory overall. First, it assumes that LustÃ¢â‚¬â„¢s PhilosopherÃ¢â‚¬â„¢s Stone is Ã¢â‚¬Å“fullÃ¢â‚¬Â. We know for a fact (A Film Fact!) that Lust has been killed at least once before thanks to Maes Hughes (RIP in pepperonis), and itÃ¢â‚¬â„¢s safe to assume that sheÃ¢â‚¬â„¢s been killed several times before then. The FMA fandom wiki puts her age at about 250 years old, and although I canÃ¢â‚¬â„¢t find any source for that, I think itÃ¢â‚¬â„¢s safe to say that sheÃ¢â‚¬â„¢s been around the block a couple dozen times. This means that sheÃ¢â‚¬â„¢d also have the normal energy drain from aging, on top of the massive dips when sheÃ¢â‚¬â„¢s killed.\n\nThird, and IÃ¢â‚¬â„¢m really surprised that MatPat didnÃ¢â‚¬â„¢t bring this up, but since Alchemy is a science, itÃ¢â‚¬â„¢s also subject to our good old friend Entropy. Transmuting energy into matter has to have a massive hit to entropy. We donÃ¢â‚¬â„¢t have anything close to exact numbers, but I think we can assume that the entropy created when turning a soul into flesh is pretty massive. \n\nAlso, and this is a nitpick, but we really canÃ¢â‚¬â„¢t assume LustÃ¢â‚¬â„¢s weight. Both Envy and Gluttony have been shown to be much heavier than they appear physically, so itÃ¢â‚¬â„¢s not outside the realm of possibility for her actual mass to be much higher.\n\nBut hey! Assuming spherical Homunculi in a vacuum, at least your math is right! And thatÃ¢â‚¬â„¢s juuuuuuust a theory! An aaaaaaanime theory!