This cel is from episode 73, during the "Christian Arc". It's slightly oversized (and wouldn't quite fit on my scanner). It's hard to say much about the cel, or about Magdalia herself, without at least mild spoilers, so if you haven't seen the "Christian Arc", maybe you shouldn't look too closely at the paragraphs below. :-)
When I first saw Magdalia (also known as Amakusa Sayo), I rather disliked her. Her character was just so good, in a self-righteous sort of way. However, meeting Sano made her lose her absolute certainty in her brother's cause, and realize that the people standing against him were not necessarily evil. In fact, she came to be rather, well, fond, of a certain chicken-headed member of the Kenshin Gumi. This made her a lot more human, and she still kept her admirable qualities. In the scene that this cel is from, despite her own injuries, she is struggling to save her friend Shouzo (with the lever that belongs in the gap across her shoulder.) She is looking at Sano, who has of course come to help her. Personally, I'm a fan of Sano and Megumi as a couple, but I can accept Sayo if I think of Megumi as not existing in this arc (since it's not from the manga, anyway). Given that, Sano and Sayo's relationship is very sweet. Sano seems to have a thing about women who are "above" him in some way.... While I suppose this isn't what one would think of as the perfect cel of Sayo, I find it very appealing for some reason. It's drawn very nicely, and it captures her in an unguarded moment, thinking of Sano.