Watch Robert Downey Jr. and Don Cheadle honor Chadwick Boseman as MTV Awards' Hero of the Ages

Chadwick Boseman's Marvel costars Robert Downey Jr. and Don Cheadle honored the late actor on Sunday, posthumously announcing him as the Hero for the Ages at the MTV Movie & TV Awards: Greatest of All Time.

In a video message, the two celebrated Boseman, who died of complications from colon cancer in August, as a real-life superhero. They both shared the screen with the actor in three Marvel films, including 2019's Avengers: Endgame.

"The second you first saw him on screen or had the opportunity to meet him in person, his energy and intensity was undeniable. There was something different and special about Chadwick Boseman," Downey Jr. said.

"Each time he stepped on the set, he inspired and influenced everyone there," Cheadle added. "And with every role, he created a new legion of fans. He had an incredible power to unify people in their love for his work and their respect for him as a person. The way he lived his life united people behind a higher purpose, and that will be his legacy."

"The Avengers have all been given an opportunity to portray characters that are meaningful and hopefully memorable," Downey Jr. continued. "Mr. Boseman truly embodied what it meant to be a superhero. His impact as a groundbreaking leading man, as an icon on screen, it won't be quantified by the box office records he broke, but by the legions of fans who will celebrate him for many years to come."

Cheadle noted, "Chadwick will be forever known as the Black Panther, but he also painted incredibly powerful portrayals of iconic and influential real men who changed the world. Thurgood Marshall, James Brown, Jackie Robinson, he brought humanity and truth to the portrayal of people who felt larger than life, and he did it in a way that honored their memories."

Downey Jr. also referenced Boseman's generous spirit, saying "he wasn't just a hero on screen." Most recently, Sienna Miller revealed he donated some of his salary so she could be paid more to appear in their film 21 Bridges.

"His list of selfless and inspirational acts and deeds is too long to recount here," Downey Jr. said. "Consistently showing up during trial and triumph for family, friends, and fans alike, some of whom were battling the same invisible enemy. He was the most heroic when just being Chad. That's when he was bigger than anyone he played on screen."

Cheadle concluded the moving tribute, saying, "We are both so proud to be part of this award recognizing him. The greatest of all time, our hero for the ages: Chadwick Boseman."

On Nov. 29, Lupita Nyong'o, Mark Ruffalo, Viola Davis, and more remembered Boseman's life on what would have been his 44th birthday. Davis, who appears opposite Boseman in Netflix's Ma Rainey's Black Bottom, honored him with a special Instagram tribute.

"Happy birthday in Heaven, Chadwick! You are still so alive to me!! I love you," she said.

EW recently chose Boseman as one of its 2020 Entertainers of the Year, and he is also set to posthumously receive the Independent Filmmaker Project's annual Actor Tribute award at the Gotham Awards in January.

Related content:

• Chadwick Boseman to receive posthumous Gotham Awards Tribute prize
• Chadwick Boseman: A hero remembered
• Chadwick Boseman remembered by family and friends on what would've been his 44th birthday