Anybody help me with a squad for trials?

[Jerran]

Hi all I seem to be having a lot of trouble with trials. The squad I currently use isn't cutting it. Currently I have Lancelot as leader, Arthur, Elimo, Zeek and Gabriella with Regil or Shion as friend although I pulled my own Regil yesterday.
Basically I need a squad for trials and am currently stuck on Breaking Barriers.
My other units (all omni or able to be) are:
Fire
Vargas, Arus, Adel, Avant, Kulyuk, Valen, Adriesta, Malef, Lyonesse, Rugahr, Ciara, Vermilion and Golzo.
Water
Serena, Elimo, Holia, Ilm, Tazer, Vern, Stein, Melord and Camilla.
Earth
Zeolite, Hisui, Lance, Quaid, Gyras, Rozalia, Lanza, Freed, Mariletta, Baro and Dion.
Thunder
Eze, Licht, Cleria, Shera, Silas and Fizz.
Light
Arthur, Gabriella, Atro, Kira, Krantz, Izuna, Regil, Sirius, Lara, Lauda, Barrel, Diastima and Ionia.
Dark
Zeek, Lancelot, Magress, Mifune, Kalon, Sonia, Zenia, Luina, Kafka and Gregor.

Also have Ark but can't progress far enough to unlock his omni evo materials. Any help would be greatly appreciated.

Thanks