  We explore some (especially, thermodynamical) properties of the dyonic
Kerr-Sen-AdS$_4$ black hole and its ultraspinning counterpart, and check
whether or not both black holes satisfy the first law and Bekenstein-Smarr mass
formulas. To this end, new Christodoulou-Ruffini-like squared-mass formulae for
the usual dyonic Kerr-Sen-AdS$_4$ solution and its ultraspinning cousin are
deduced. Similar to the ultraspinning Kerr-Sen-AdS$_4$ black hole case, we
demonstrate that the ultraspinning dyonic Kerr-Sen-AdS$_4$ black hole does not
always violate the reverse isoperimetric inequality (RII) since the value of
the isoperimetric ratio can either be larger/smaller than, or equal to unity,
depending upon the range of the solution parameters, as is the case only with
an electric charge. This property is apparently distinct from that of the
superentropic dyonic Kerr-Newman-AdS$_4$ black hole, which always strictly
violates the RII, although both of them have some similar properties in other
aspects, such as the horizon geometry and conformal boundary.
