City Square Mirage Interaction

Normally this mirage has to accompanied by the mirage boss but he is nowhere to be found. And because this map has 3 bosses, even if the mirage takes one boss and leaves others outside the mirage map and the maps boss can not be killed as on the image. Also it is counted as there is map boss in the mirage and this affects the eldritch alters as well as the mirage mechanics as well. https://prnt.sc/OzLtyEN-a-5q