Upper figures: X-ray morphology of XLSSC 116 as a function of energy band. The image is CFHT-LS i′ with X-ray contours overlaid. Crosses indicate the position of the surface brightness peak in each selected sub-band. The right panels show three point-sources in the vicinity of XLSSC 116 with spatial scales and contour levels matching those of the main image. They illustrate the size of the XMM-Newton PSF at the location of the cluster. We note the presence of a point-source in the [2−10] keV band west of the cluster centre. This source is masked out in the X-ray analyses. Lower figure: zoom on the same i′ image with Serna-Gerbal substructure 1 shown as red squares and substructure 2 shown as blue squares (see below). Galaxy redshifts are also shown.