This is a relatively straightforward encounter, which is mainly a boss rush mode. While there may be smaller enemies on the stage, you can completely ignore them as there will be an excavator that will help you clear most of the trash mobs. The only thing you need to concern yourself with is having enough Single-Target damage to deal with the bosses, which consist of Crusader, PMC Power Loader, Black Market Apache, and Goliath.
When building a team for this stage, you will want to mostly bring along Piercing Single-Target damage dealers such as Mika and Iori. You can also consider bringing along an Explosive AoE to help clear out trash mobs. Tanks or students with CC effects are also not a bad pick-up for this stage if you are struggling to survive or need to stun the final boss to cancel his nuke skill.
Note that characters listed here are only some of the viable options