When starting the stage, there will be 3 Automaton units and 1 Guard Tower. Before we get started, it is important to note that team building will be an important part of clearing this stage, so we suggest taking a look at the portion. However, to summarize, you will want a DEF tank in pos 1 and 3 while bringing an EVA tank for pos 2.
The main gimmick of this fight is when damage is dealt to one of the Automaton units. That damage is then reflected back onto the Guard Tower. Characters like Iori have their EX Skill hit both the Tower and Automaton by positioning Hoshino in pos and then using her EX Skill to push the Automaton closer to the tower. Note that all Automatons have 2 lives, so they will be revived when they are first defeated.
Note the position in which you place your students will matter; both pos 1 and 3 receive an Evasion debuff. While pos 2 will have a DEF debuff applied on to them. This means you will want to bring a DEF tank for pos 1 and 3 while having an EVA tank for pos 2.
You’ll want to bring a Piercing DPS for this stage, as they all have Heavy armor. Then, the rest of your team can be filled with your generic supports and a healer to keep the team alive.
Note that characters listed here are only some of the viable options