Spear Main + Valkyrie + Taoist.
Burning snakes for fun. This is probably the easiest way to kill the boss here even with low gears. Ever seen 813K+ damage?
Spear Main + Monk + Tarkan.
Monk hits like a drunk old man but it takes a lot of turns to beat the Boss here that he is actually useful working together with melee mercs.
Spear Main + Hwarang + Champion.
This one is another simple mission, if you can manage to lure the boss away from mobs. The objective is to meet and greet a big mother snake boss after killing some of her children on the way, and torture her until she tells you to stop. Basically, it's a boss spiking mission.