How to defeat Raiden Ei? She sometimes throws all units into the rift in one turn with one ult, and if there are units left, they cannot get through this rift and fall
the gimmick is that she doesn't uses her ult on the civils so your units needs to use them as meat-shields
i did it this way 1.XianYun as a suicide bomber 6.biggest corrupted hilis with electro immunity 1. geo shaman with electro immunity to make jumping platforms and body blocking the civils
1st. attack her with XianYun (if she removed the half of Raiden health then quit to the world map and save otherwise just reload the last save)
2nd. attack her with XianYun again, this time try to avoid hitting many civils ( if raiden already had half of her health removed ,this will automatically start phase 2 " the shield phase", also the attack will slightly stun her , giving your other units a turn to run to safe zones
3rd. run for safe zones and use the shaman's skills to block the civil in good places
4th. play super safe and only attack if you know she can't use her ult (if she's far away then ran away from her to bait her to get closer
5th. after her shield is broken rush her with everything you have got.
there're better strategies probably tho