here's my formation

spear/bt/lady knight

archer/main(gun)/exo

oracle/inventor/monk

btw monk is a must 

sop is good if only the enemy att once..

if for combo, still not good...

protect gives higher def than sop, but sop gives def on each att( single att, not combo)...

From your formation, I assume your main is Musician yes? If you want to do PvP AoE build, I suggest to swap your Jannisary with Cannoneer, so partner up with your Artillery it would be doing more damage either skill wise or normal attack, plus the fact having an Inventor inside your build will add up with his catapult summon skill. Put your Monk and Oracle in same line so easy to HG and put Artilery, Cannoneer and Inventor on middle line to give them Seth for better damage and coverage in single turn.

Thats my suggestion tho, do you have any mercs in future you want to get?

Anyway, I'm Naradia from Sikyon, Main level 111, so slow leveling these days

Gorky Park/ Goncourt the Ghey

wah so good lah you, so far i got only 1 War Cay [I] from Goncourt.

Can, when you hit 97++ i'll ask them to invite you. If you join now you will feel VERY displace as i am the lowest lvl char there.