ColinHunt Know their weaknesses XD. I can recommend a team with Robin (magic) Altina or Aka (poison + magic or melee), Carina (heal and buff) and Simon (corrupt, stun, dominate and heal).
I managed to do the mini-boss without too many difficulties with that team.
I'd say always nuke the clown (Hollow Courtier) with fire first (Robin + Altina)
Dominate the Lust demon
Corrupt or stun/blind the Manawing
Stun and poison the Wall
Kill the Fleeting glimmer if there is no clown left (he resists most things and is immune to physical, but he has low hp)
Robin and Altina are dps, Simon is stunner (with dominate, unified and corrupt) and Carina is buff and heal