The Demo Is Out Now
Players can choose one out of three companion animal spirits and depending on the choice the personality of the characters is affected and the dialogue changes.
Youmu's shot type is almost exactly the same as in TD with small differences depending on the animal spirit you choose, in fact they are the same exact skills and spellcards as in TD.
I completely forgot about this before, but there are also some notable design changes:
Her eye color is now inarguably white/silver. In Ten Desires it was still much more ambiguous due to her eyes being much darker.
Prudish elements like the drawers are also no longer present and the vest is now very light similar to the design in the fighting games. As a result, she has a much more feminine-looking figure now.
The double white stripe on her ribbon is now canon. While ZUN had used a single white stripe in the C67 circle cut before, there was no precedent for a double white stripe even by the other official illustrators.
The snake(?) head on her phantom-half and possibly also the changes to the pattern on her dress are most likely story-related.
Actual spoiler:
Wolf Youmu is absolutely savage.