A blade is provided for the cycloidal marine propellers or cycloidal aerial rotors. Said blade is provided with the capabilities, in response to the control system commands to dynamically and in real time; flex itself along its chord in any required way, vary its relative pivot point position, change its planform by extending or retracting a trailing edge extension, differentially if needed on the right and left, turn the flap along the trailing edge in either direction or allow it to be turned by the flows. Said blade is also optionally provided with one or more elastic trailing edges whose stiffness is dynamically, and possibly differentially along the blade span, variable by the control system. For the reversal of the leading and trailing edges for operation in reverse airflow and other conditions the blades are provided with edges that can be made rigid when functioning as the leading edge and flexible if needed when functioning as the trailing edge. Also the blades are provided with the capability of varying their cross-sectional profile thickness and reshaping it. Finally the blades are given on command flow permeability along much of their surface. These capabilities will enable each control system controlled blade to continually optimally adjust to and make the best use of its immediate operating environment as it travels along its trajectory within each revolution.