Robot Duelers

$\mathbf{Using}$ $\mathbf{the}$ $\mathbf{clues:}$ $\\$ 1. ${\color{#D61F06} A}$ isn't weak to ${\color{#3D99F6} B}$ and ${\color{#D61F06} A}$ is weak to the robot weak to ${\color{#20A900} D}$ (not ${\color{#20A900} D}$ itself) meaning ${\color{#D61F06} A}$ is weak to the leftover robot, ${\color{#CEBB00} C}$ . $\\$ 2. ${\color{#CEBB00} C}$ is weak to the robot weak to ${\color{#3D99F6} B}$ (not ${\color{#3D99F6} B}$ itself) and ${\color{#D61F06} A}$ isn't weak to ${\color{#3D99F6} B}$ , meaning the leftover robot, ${\color{#20A900} D}$ , is weak to ${\color{#3D99F6} B}$ $\\$ 3. As ${\color{#CEBB00} C}$ is weak to the robot weak to ${\color{#3D99F6} B}$ and we know ${\color{#20A900} D}$ is weak to ${\color{#3D99F6} B}$ , ${\color{#CEBB00} C}$ is weak to ${\color{#20A900} D}$ $\\$ 4. We have not determined who ${\color{#D61F06} A}$ is the weakness to, and ${\color{#3D99F6} B}$ is the only robot without a yet determined weakness, meaning ${\color{#3D99F6} B}$ is weak to ${\color{#D61F06} A}$ (the answer) $\\$

${\color{#D61F06} A}$ is weak to ${\color{#CEBB00} C}$ who is weak to ${\color{#20A900} D}$ who is weak to ${\color{#3D99F6} B}$ who is weak to ${\color{#D61F06} A}$

A cannot be weak to A, B can't be weak to B, C can't be weak to C, and D can't be weak to D, shown in clue 1. Clue 5 tells us that A can't be weak to D because A can't be weak to A which is weak to D, nor can A be weak to D who is weak to D. Clue 6 tells us that C can't be weak to B because C can't be weak to C which is weak to B, nor can C be weak to B which is weak to B. Clue 7 tell's us A isn't weak to B, so A must be weak to C. Now, the only person who can be weak to B is D. Finally, we can fill in the blanks in clues 5 and 6. Since A is weak to C, C must be weak to D. Finally, C is weak to D, so D must be weak to B. (You might have not included the 2nd to last step, which is fine and also produces a correct answer to the asked question.)