Tsubasa: Reservoir Chronicle 10: 10/24/15
Tsubasa: Reservoir Chronicle Volume 10 by CLAMP ends the story involving Ashura-o and Yasha-o and takes the travelers to a new world, Piffle, that will lighten the mood after so many heavy revelations.
The Ashura / Yasha arc, while heavy duty, is one of my favorites in the series so far. There's an element of time travel to it, and an example of how a single snap decision can change everything. The translation notes for this section are especially interesting.
Yuko makes an appearance. Apparently the travels between the worlds have been orchestrated by outside forces. She has put a stop to that. The travelers will now be on their own and will be in more potential danger than ever before. I always get a pang of excitement when the Dimensional Witch appears. I'm more a fan of xxxHolic than I am of Tsubasa.
The Piffle World involves a series of races. The prize is the ultimate power source. As you can imagine, it's one of Sakura's feathers. The race brings together all sorts of CLAMP characters from various series, enough of them that even Syaoran and the others notice. It's a fun arc and one where Sakura really gets a chance to shine. The races remind me a bit of the French / Japanese anime Oban Star-Racers.