As D. Corvus can handle all damage needed and is extremely tanky, team compositions revolve around supporting him with tanks and healers, or other sources of damage mitigation, or CR/CD manipulation from the likes of Iseria and Lots.
The only requirement is to bring at least one healer and one source of mitigation, as sustain is necessary for D. Corvus to do his job over the many many turns of the fight.
Iseria is a notable support unit as the only source of a full CD reset, which resets D. Corvus’s S3, and is highly useful to bring into teams with multiple revivers.
Dizzy is a very strong debuffer, and can single-handedly lockdown entire teams without cleansers.
Against damage heavy teams, running multiple tanks, bringing both Adamant Shield + Aurius, is important. Water’s Origin Ruele/M. Chloe are strong Revive options, while C. Armin/Elena can setup Invincibility.