The Mind-Master is a supervillain in the Marvel comics - an enemy of Daredevil and Black Panther.
Ruffio Costa ordered Bernie and Jo-Jo to kidnap Keith Mallory, the son of multi-millionaire Robert Mallory.
Bernie and Jo-Jo returned with the kidnapped Keith and they called Robert to demand the plans to his tidal station, planning on selling it to oil cartels for 50,000,000. Bernard (Bernie's given name) was panicking about the Black Panther looking for him and demanded payment so Costa ordered Willis to shoot him. The other kidnappers panicked, begging for mercy, and Costa ordered Willis to back off.
Outside, the Maggia men opened fire on the Panther and, though he put up a fight, took him captive. Wanting to hold the Panther for ransom, they called his ally, blind attorney Matt Murdock, not knowing Murdock was really Daredevil. They ordered him to bring 5,000,000 to a specified location, and Costa waited, pleased his plans were working out. Keith and Panther were captives in metal restraints and Keith was shocked when Panther managed to break free without being electrocuted. He had to leave Keith behind as he broke out, fighting his way free past the Maggia men outside and riding out on the car of Gil and Junior. Daredevil stopped their car and punched Gil, then avoided Junior's gunfire as Panther disarmed him; they threw both defeated men into the dumpster.
Daredevil and Panther, working together, defeated Costa's men who went to pick up the ransom, then rushed back to Costa's place, easily defeating his men, including Boxer and Freddie. Unknown to Costa, the base he was in had been a weapons research lab years before. When the machinery exploded, he was caught up in the energy barrage of neutron streams and they granted him super powers, heightening the power of his mind to an infinite degree. When the smoke settled, Costa was in a yellow-and-white costume and he immediately attacked the heroes, calling himself the Mind-Master. Mind-Master forced Panther to attack Daredevil, and the villain watched the fight as he ruminated on his own potential
Daredevil soon managed to knock Mind-Master aside, punching him before he could build up enough power to send off an incinerating blast of mental energy. Losing his concentration on Panther, Mind-Master tried sending blasts at the agile Daredevil, who was narrowly saved by the Panther when a generator almost fell on him. Mind-Master resisted their blows, feeling more powerful every moment, and he shot the Panther aside. Daredevil struck Mind-Master repeatedly before the villain seemingly killed the hero in an energy blast.
As Mind-Master advanced on Panther, his power suddenly left him. Unable to reach his gun, Panther easily defeated Costa.