"You almost hurt my Onii-chan," she said, with a tone as cold as the very depths of space, even as the odd polearm that was the first thing she'd ever managed to Imagine materialized in her hands. "For that, I cannot forgive you."
Lack of sleep and excessive over dose of caffine lead me to parsing the above to mean that Hotaru-chan is seriously crushing on Shiro-oniichan.. Which means that post Mistress Nine events, which is likely when Shiro is likely to move on, Hotaru-chan would likely be insistent on going with him...
Now, there's two ways of playing with that in the main story itself, one of which is that Hotaru-chan goes along with him, and everything plays out with her as a minor character, or, you can have Shiro leave her behind. But after he arrives and meets up with Saber and starts playing Merlin to her Arturia, but shortly thereafter, Hotaru-chan arrives... in her Mistress-Nine persona and plays Morganna to Shiro's Merlin (
Lack of sleep and excessive over dose of caffine lead me to parsing the above to mean that Hotaru-chan is seriously crushing on Shiro-oniichan.. Which means that post Mistress Nine events, which is likely when Shiro is likely to move on, Hotaru-chan would likely be insistent on going with him...
Now, there's two ways of playing with that in the main story itself, one of which is that Hotaru-chan goes along with him, and everything plays out with her as a minor character, or, you can have Shiro leave her behind. But after he arrives and meets up with Saber and starts playing Merlin to her Arturia, but shortly thereafter, Hotaru-chan arrives... in her Mistress-Nine persona and plays Morganna to Shiro's Merlin (