For anyone having trouble with Ciella and Miera's challenges, Ciella's challenge is easy as long as you have a keyboard warrior resistance card, even if it is a 1 star, and atleast a girl with level 3 dash. Simply run up to the orb, mash as fast as you can, then dash away while killing all the impersonators you see on the other side of the map. Bait all the bashers and other enemies and then quickly dash over to the orb and mash as fast as you can and repeat. The timer resets when you turn in the orb, so you can grind bits out before turning it in so the next orb is faster.
Miera's is very challenging unfortunately. You want a very strong, preferably max card (I used Nicole) with high damage and energy. I used the level 4 teleport girl, and would instantly teleport up onto the pillars, look for a impersonator or keyboard warrior, and teleport to them and kill them. Don't look at the megabytes, only kill kilobytes if they're nearby. Bashers and spammers have a lot of health, I would try at least shooting at the spammers though, as they do slight aoe damage to enemies if you shoot them wrong.
