Asuka

This monster is only encountered during the battle with the Ikaruga Mk.II, and only if it uses Alarm to call for backup. They really aren't much stronger than some of the high-tier Aircraft-type enemies, but are a massive annoyance because the Ikaruga can't be attacked as long as they are in the battlefield, and if you don't concentrate in defeating the Ikaruga, it'll continue summoning them eternally. However, as they do have Induced Explosion in their skillset, killing them could benefit you, as the resulting blast will end causing a decent amount of damage to the other Asukas and to the Ikaruga. Just don't get too sidetracked with them.