Do not shoot Moji when she is using her Magic Barrier. If you did, retreat because you are less likely to win the 1v1 fight with the Moji as she has higher DPS and burst damage.
In close range, depending on their timing of popping their Magic Marks on you, Moji can deal up to 1000 damage per second. Never give her a chance to flank and make sure to focus her down after she pops her Magic Barrier and scampers away.