You have to have some clever placements before you start her Spell 1, cause you don't want to have moving around once it starts, the spell is static iirc. Placement for the areas where you cannot do damage is always the same.
For most bosses of this nature on higher difficulties, you need to take advantage that they are on a lifebar count.
is the first super boss that you need to "trick" the lifebar, but she makes your life easier by only having Grit, and not Iron Wall. All subsequent super bosses that I encountered so far,
all got Iron Wall, and some levels of HP Regen. Boss AI will use Iron Wall, and Grit on 30% HP.
On Lunatic only, any Faith from goons will also activate at this point, those Kappas will all need to be clapped before you take even
on. Later on,
's King Demon Eye she summons on her first spell also has Faith, it goes without saying that you need to take him out too.
So what you need to do is, on her first spell,
with only little health remain and past it back to her, she does whatever and pass it back to you. You break the spell, she activates
, then you bum rush that entire health bar, but must leave 1 active unit to use the bomb and pass it back to her, so you don't get completely smashed by
power penalties when she MAPs you. You still get -30, but it is better than -200 if you leave the field on. If you survive with most of your units intact at this point, you can pretty much press buttons and win. It took a while of planning and inching, but I beat
with 0 deaths (if you don't count Hourai dolls :v )
is much easier to pull off, because she does not have a starting MAP to pressure you with. Everyone afterwards, I would assume at this point, has a starting MAP making it much harder. At least the ones that I have seen so far are quite weak, that might change.