'With twenty-three days left to prepare, there was no amount of strategy that would be enough. My paranoid brain's been put through the wringer with the information I have.
Count Khalim can help Daiyu with anything equipment or land related, Arabella can help with anything related to the troops. We have no shortage of strategy for a normal war—as normal as a war gets.
But with six elite soldiers potentially showing up, all with affinities and five more powerful than Frost, a different approach is needed. Our best defence is a good offence at this point.
We need magic, we need spells and we need powerful ones that can change the tides. Hotaru said she could learn some sort of spell to help her fight from Feyan, but Hotaru's a healer at the end of the day.
She's more useful after something bad happens, not before. She's our anchor, our failsafe to bring us back into the fray, not to be in the fray herself.