Event Strategy Log: The Case of Rare Ichigo's Overpowered Ultimate Skill

To farm efficiently, is a formation with two rare swordsmen with the special bonus mandatory? (Needs verification) Excluding Ran-chan, the others were still in training, and considering luck factors like Toukigaki's initial placement, I managed to barely win even with the average formation level being 10 below the recommended level. There were also mistakes like mis-swipes during battle, so if I hadn't made any mistakes, I might have won with more room to spare... I can't say for sure, but I felt that to farm the high-level stages of this event as easily as possible, 'Rare Ichigo-san' with the special bonus seems to be the key. Being able to take heavy enemy attacks with no damage is too strong! If you stack the ultimate skills before taking damage, the guard increases to two uses, making it easier to prepare for heavy attacks. (The unclear stacking limit is a bit of a drawback though.) My impression is that 'Rare Ran-chan' might not be mandatory(). While they are normally useful due to having the special bonus, it feels like they could be substituted with units having lower-tier buff/debuff ultimate skills. If operating with two rare Awata-guchi units, instead of Horikawa-kun, a tantō or wakizashi with an offensive ultimate skill might be better for the panel missions. (Is Sayo-chan a good match??) If there's demand, I'm considering uploading the battle content from this event to my video channel.