It'll be difficult for sure. Go check the wiki page of the event, they have videos of the maps. Check what units will appear and remember that you can let a whole 9 of the enemies pass to still complete the map. Make the toughest ones pass and try to kill everything else. If possible you might want to try to get those last 5 lvls for Soma and CC her, it will make things easier with a longer range.

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Crisis of the Fairy Village - Millennium War Aigis Wiki