Episode 21:
Aa! Akogare wa Shiroi Tsubasa no Tenshi!
Ah! The One I Yearn For Is A White-Winged Angel!
Manga Chapters: 089, 074, 079, 034
External Links:
Gateway to the Goddesses [089]
Gateway to the Goddesses [074]
Gateway to the Goddesses [079]
Gateway to the Goddesses [034]
TBS (Japanese)
Wikipedia
Token Asian's Anime Blog

This episode is based most off of chapter 89 of the manga, with bits sprinkled in from chapter 74, a little bit from chapter 79, and a little bit of reference from the movie.

Regarding the timeline, I find it interesting that they decided to have World of Elegance's appearance so soon; then again, they had Holy Bell introduced in episode 03 and she's made the occasional appearance since then. Also, World of Elegance is introduced before Skuld's Noble Scarlet in this new timeline. Also, they reveal Urd's half-demon heritage before the Lord of Terror arc in this new timeline.

This episode begins by wrapping up what had happened in the last episode, by explaining that Urd was the one who made the chemicals that turned Keiichi into a women (although Skuld was the one who wanted it). That bit didn't make much sense to me even when I found it fishy that Skuld would have access to potions... besides, don't you think Urd would think something fishy was up if Skuld made such a request? Eh, c'est la vie. Originally in the manga, it was Skuld who was having fun dressing Keiichi up like a Barbie doll, not Belldandy.

This part is interesting, after Keiichi turns back into a full man. This seems directly ripped from the movie, since the movie shows Belldandy singing with Holy Bell in the beginning after the opening sequence with Morgan LeFay. Belldandy seems to have a penchant for singing to trees in the animated versions of Ah! My Goddess... this was never apparent in the manga.

The manga doesn't really delve into angels until the Lind arc. Urd's explanation to Keiichi is then new, about angels being a supporter.

Let me take this moment to say this... Urd's outfit is awesome.

Skuld being impressed by Holy Bell is basically taken from the movie and chapter 79. However, in the manga, Skuld never confronted Belldandy about acquiring an angel, and instead sought out Urd to not find her and instead find an unguarded angel egg.

The conversation between Skuld and Belldandy takes a nasty turn (from Skuld's perspective) which never really happened in this context in the manga.

"Thinking about it, the conflict between Skuld and Belldandy is likely borrowed from the bicycle story and Skulds frustration that Belldandy would not help her, at least in her mind (even though letting go of the bike was exactly what Belldandy needed to do). I think cutting that story out really did a disservice to the TV series." - Miss Izuko

Skuld attempting to manipulate a nut is taken from chapter 74, when she decided to take training seriously after overcoming her overreliance on machines and other people. The conversation between Urd and Skuld also took place in this chapter, although Skuld never decided to use a gun to levitate it...

The conversation regarding holding enough power to control an angel is displaced. Originally it was between Urd and Belldandy over an unconscious Skuld after she fainted frm swallowing the angel egg (thanks to Miss Izuko for that correction).

The conversations regarding Urd's angel are new the the anime sequence of events, since the only person who knew that Urd had an angel was Belldandy in the manga (although she still didn't know why Urd never used it).

Originally, it was Urd who confronted Belldandy about going to a walk in chapter 89. The conversation's fairly different, though. It originally had an added piece from Belldandy, where she said something along the lines of being overjoyed when she got her angel, since "it was like making a new, very special friend. I was overjoyed. The closest, most understanding existance in the world. Like a mirror, reflecting my innermost soul." (Dark Horse) After that, Urd walked away saying that the reasons why Belldandy was overjoyed were the same reasons she was so terrified. This is absent in the anime since Belldandy already knows of World of Elegance's appearance; she never saw it in the manga until it's debut arc.

When Urd attempted to call her angel, she originally didn't have her little monolouge. The part about Skuld thinking of being a rival with Urd is kept, although the little fantasy scene with Belldandy being her angel is new... and a little twisted.

The part about the virtual device is all new in the anime, although it looks like the Bester Tester from another arc and Mr. Memory from the movie.

Originally, the manga has Belldandy read runes, but that is absent in the anime. The runes served the purpose of reuniting Urd with her angel, but I guess not in the anime.

Urd observing Skuld is new, as well as her reminiscing. The silhouette of Hild is new to this timeline. The flashbacks are almost all new, except for when the angel appears.

Urd seems to be wearing her old hairstyle and Goddess Standard dress in the flashback, though...

Originally, Belldandy wasn't present when Urd had her angel.

The part about Skuld taking apart Keiichi's stuff in order to create the Power Amp Alpha-707 (it sounds a lot cooler in Japanese) is kept, although the reference here is a little short; originally, Skuld got the idea from their earlier encounter with Marller in Queen Sayoko's castle.

This part is kept more or less completely faithful, although the part about training is new and originally Keiichi was the one who pressed the switched, albiet accidently.

The part about the water shield is kept more or less faithful also. Skuld was originally floating in the air (or something) instead of being held by Keiichi.

The part about the machine actually sucking out magical energy is new, and adds an element of urgency to the plot.

Urd's line "an angel is absolutely obedience to it's owner" had more of an impact in the manga, since she warned Skuld earlier when Skuld had Noble Scarlet (and accidently told it to go back into it's egg).

Belldandy originally encouraged Urd with runes, and Urd's admiration of Belldandy is new to this scene.

Urd giving Skuld the angel egg is new, so we'll probably not see a faithful adaption of that storyline in the future... in fact, we probably won't see it until the Lind arc's adaption.

The very end, with the phone call, is originally from chapter 34, the beginning of the Lord of Terror arc. It's more or less new material due to the new adaption of the timeline.