I know you said the mission was intended for upgraded units, but I just wanted to confirm that, you can in fact still beat it with fresh lv1s. I used x1 Chateau (My favorite~) x3 Theano, x1 Covenant, x4 Cornucopia, x1 Sampo. Unfortunately, I didn't get to savor eating the Queen cause it crashed when she was releasing prey lol. Fun level!