Cast High Entropy Alloys (HEAs) derived from the Cantor’s composition may represent alternative substitutional solutions to the superalloys which are constituted for more than half of the critical elements nickel and cobalt. Metallography control (MC)–alloyed HEAs constituted by a Cantor’s type matrix associated to an efficient interdendritic network of MC carbides, have demonstrated promising creep resistance at elevated temperatures. Regrettably, they also show poor high temperature oxidation resistance. This bad oxidation behavior is possibly due to the deleterious effect of manganese and to a too low content in chromium. New alloys were elaborated and tested in oxidation at 1100°C with thermogravimetry follow–up and metallographic characterisation, and their creep behavior was controlled. With less Mn and more Cr than the original alloys, these new alloys demonstrated significant progress in oxidation resistance. These changes in chemical compositions did not modify their creep resistances which were globally maintained, for the carbide-free alloy as well as for the MC-containing ones. These Mn-decreased and Cr-increased MC-containing alloys can be considered as low-cost alternative to polycrystalline Ni or Co-based superalloys for working in moderate conditions of corrosive fluids and applied mechanical stresses.