Why Sirius was Chosen as Godparent & Sirius' sacrifice

[vmonte]

No: HPFGUIDX 105836

Jen wrote:

Now back to Godric's Hollow. What if Sirius being willing to die for
Harry has more significance than previously thought? What if James &
Lily chose him for this specific reason? In other words, there's
more to this guardian selection, some additional protection conveyed
onto Harry if Sirius does indeed die while attempting to protect
him, similar to but not as powerful as Lily's sacrifice. Sort of a
strengthening of Lily's sacrifice.

This is probably something Dumbledore is unaware of until OOTP, or
perhaps is still unaware of, something between Lily/James/Sirius,
that may even involves a charm cast between them. For we know that
Lily's sacrifice is *separate* from the charm Dumbledore placed on
Harry before he was delivered to Petunia.

And Sirius, loyal dog that he is, makes a choice. He can stay,
cramped in Buckbeak's room, awaiting execution. OR, he can die
fighting and give Harry much more protection than he will ever be
able to give alive. Given that situation, there's really only one
choice Sirius would make.

vmonte responds:

This is a cool theory! JKR did say that there was a reason why Sirius 
had to die. Your theory may be why.

vivian