re: Crackpot ASOIAF Theories SPOILERS

Well since this does say crackpot...and I think I remember someone hinting at something like this, I'll put this here. (Not my theory, just ran across it)

Varys is a Blackfyre descendant, and he and Illyrio are the chessmasters running the conspiracy to put Illyrio's son Aegon Blackfyre on the throne.

First, we know that Varys and Illyrio are definitely running the Aegon conspiracy, Blackfyre or not. The evidence for Aegon being a Blackfyre is extremely strong, partly because of the Golden Company switching sides, and partly because of his parentage.
The parentage question really locks things down. Let's pretend for a moment that Aegon is really Rhaegar's rescued infant. Why were the other two known Targs, Viserys and Dany, on the run going from house to house for most of their life? Why did Illyrio wait until a couple of years before the start of the series to finally shelter them? We know from ADWD that Illyrio was in fact sheltering infant Aegon right after the war. Why not the other two?

Illyrio's wife, who he loved dearly, had silver hair. Coincidence? It's possible, but come on. Hair color is a key component to mysteries of parentage in this story. It's either an intentional red herring (and an excellent one) or Serra was a Targ by blood. Now, if she's a Targ, why was she a Lysene commoner when Illyrio met her? Wouldn't she be in Westeros as a noble woman? No, because she's a Blackfyre, and the family is scattered and poor. Illyrio and Serra are Aegon's parents, and Illyrio out of love for his long-lost wife decided to carry through elaborate plans to finally place a rightful Blackfyre heir on the throne - with the name of Targaryen, no less, as he deserved.

Let's move on to Varys. The two master manipulators met years ago and became wealthy over time. Varys supports Aegon Blackfyre over the Targaryens and anybody else; he's been scheming to put him on the throne for years.

Varys shaves his head, and GRRM specifically describes his head as looking like an egg. Isn't that funny? Don't we know another silver-haired Targ with an identical description and method of hiding his hair? Could Varys be pursuing this incredibly long con entirely out of loyalty to his life long friend Illyrio? Perhaps. When you combine the other evidence, though, it makes a stronger and stronger case that Varys is related to Serra somehow. Two Blackfyre descendants, the family broken apart, one a prostitute (right?) and the other an orphan in a traveling circus of some kind. Maybe when Illyrio and Varys became rich, baldy tracked down his long-lost sister that he remembered from the years before their parents died. Maybe Varys is Aegon's uncle and Illyrio's brother-in-law.

TL;DR: Varys is a Blackfyre descendant. His sister Serra married Illyrio and their son Aegon is currently conquering Westeros.