Ryoma Tank

Nino with LnD, Despe, hone +ATK (Max) + Moon Bow & Reposition
Ryoma with Fury, Vantage, hone +Spd (Max) + Luna/Moon Bow & Reposition
Olivia (basic set)
Robin Blue (basic set with hone DEF)

Move Ryoma to middle in the danger area of the 1st sword calary, Robin and Olivia beside. Later everything become easier, kill one by one when you had Olivia dance and Nino to kill the Blue Lance and Reposition to move Olivia to the back side.

Ryoma

Nino

Olivia

Robin (M)