Filling up plot holes with rubber cement

In trying to write WDKY24, I have come across two major blocks:

(1) Anubis' real history. Who is he really, where did he come from, how did he get his powers the first time, and who was behind bringing him to Japan THIS time? What's his grudge against the Pharaoh, anyway? Why does he look so different, and yet he's familiar with Sphinxes, Pyramids, and other Duel Monsters? How would he fit into the AE saga, anyway?

(2) How the hell did Yami Yugi even beat Anubis when:
a) He didn't have Double Spell, he had Diffusion Wave-Motion in his hand
b) the Pyramid of Light card in the movie DOES NOT chain to Andro Sphinx and Sphinx Teleia to destroy them when it is destroyed, the way it does in the TCG
c) Kaiba tried the same method of destroying the PoL with the Blue-Eyes Shining Dragon, and it didn't work?
d) Freakin' Theinen had 35,000 ATK points! Not even Noa's Shinato had that much!

Well, so I filled in the plot holes. My obvious answers, that you should expect from WDKY24 without much fanfare:
a) Yugi actually DID have Double Spell in hand. He did not have DWM.
b) The Sphinxes, whose cards were NOT shown clearly in the movie, will have the sub-text/requirement of being destroyed whenever the PoL is destroyed/removed from the field.
c) That'll get explained. :}
d) Math. Lots of it. (Moi? But yes, I did it, and IT WORKS!)

I'm actually kind of proud of myself. Now if only I could WRITE the damn chapter instead of scribbling notes!