Another connection to the MCU is Dr. Foster, voiced by Laurence Fishburne, who played the same character in Ant-Man and the Wasp (2018).
The monsters that star in the movie Lunella, Devil and Casey go to see, "Droom v. Torg: Dawn of Destruction", both originated in Marvel comics. Droom first appeared in Tales to Astonish #9 (1959) and Torg in Sub-Mariner #55 (1972).