Soul Hackers Beelzebub in 3 turns

The MC needs to spam Magic Mirrors, and Bel needs to take damage from his own Mazionga at least once.

Both Heimdall and Metatron will use Judgement/Heaven's Vengeance non-stop.

Nemissa will heal on turn 1 and 2, then will use Kurikara Kokuryu on turn 3. If she acts before Metatron during turn 3, then I need to restart. Metatron has 16 AG, so a Nemissa with 20 or less AG should be able to do it easily.
Remember to put her on the back row to reduce her speed. She also needs to have 44 magic (assuming you're playing on Hard)

Ym and Cybele will buff Nemissa and debuff Bel. If during turn 3 Metatron deals 4000 damage or less, then congratulations! Beelzebub has 4k HP left; meaning that Nemissa will be able to deal 1000 damage four times thanks to the buffs and debuffs.