so , i've tried ultimate Yata just for the heck of it with my team.

I took around 75-80% of it's hp before dying. I legit think i could have won with a bit more luck. I got no recovery items that fight , and my soul had a light wepon equipped. I also had a terrible support eidolon (just a prisoner of light)


Honestly , i went in just to see how big of a diference it is from the 20 stamina one , and expected it to demolish me.
Outside of increased defense and hp , it didn't seem all that different honestly