Who in blue perfect hell thinks DC would win? lmao. RKT is omniscient, he would know all their weakenessess, not to include the Destroyer Armour, but to be serious; he could take this by himself and solo the dc lineup.
ZH Parallax solos, since he was a multiversal-level threat. He was only defeated after he spent most of his energies destroying the universe, creating a new one, and then fighting the Spectre. He didnt completely defeat the Spectre, but did seem to KO him for a few pages. (Basically cause he'd spent his energy by then and the plot required the other heroes to actually get the "win")