A1: Level up to around 45+, and have mages with earth-like element moves.
Earth force beads work here as well as Kyril's x3.0 attack (swallow rune) DESTROY ALL WEAK enemies first. They shall cause an annoyance to you. AND ALSO stay on the element you're character is accustomed to, like Andarc+Lightning space. Overall, the people you should have are : Kyril, Andarc, Seneca, Kika, Corselia, Simeon(if you want to replace Corselia) and others ESPECIALLY Tristian, since he's super strong at levels 40+. Good Luck!
-Steven^^ (Too long?)