DOCTRINE
Use Splatter to force Solomon off his firing position while avoiding the bishop's diagonals yourself. Save The Cube for meaningful incoming damage, then check the ground before leaving it because his pieces may still threaten that location.
Use Puddle Punch to disrupt Solomon's position when teammates can follow. Choose a route through the fight that leaves room to turn or exit, rather than rolling Goo Ball along every marked square to reach him alone.
Use Goo Ball to threaten Solomon while your team contests the objective. Change direction when he moves the queen onto your route; your resistances reduce damage but do not make it safe to keep taking every hit.