A key to making this work is to give the Manhunter from Mars villains worthy of his power.

Source: https://www.cbr.com/martian-manhunter-status-quo-powerful-dc/

But when he was revealed to be DC Comics legend Martian Manhunter, aka J'onn J'onzz, people went bat-s**t crazy.

Source: https://collider.com/arrowverse-superheroes-dcu/

Creeper learns that that the Commodore knows who he is, as they deal with the aftermath of Codename: Assassin’s fight with Manhunter, and Warlord goes looking for Orion in an attempt to fix some of the problems he and Starman started.

Source: https://insidepulse.com/2023/10/16/the-weekly-round-up-723-with-nights-1-batman-robin-2-avengers-6-a-tribute-to-keith-giffen-more/

Martian Manhunter and Fire had a surprising fling, despite J'onn's fear of fire, making it an unusual affair for the hero.

Source: https://screenrant.com/10-shocking-justice-league-romances/

Martian Manhunter is a special kind of hero.

Source: https://www.cbr.com/dc-superheroes-villains-control-not-corrupted-anti-life-equation/