He-Man vs DC Comics

Connection:

Both are superheroes who are originally teenagers (Prince Adam and Billy Batson) who turn into big and muscular powerhouses (He-Man and Shazam respectively) whose powers is given by a magical figures (Sorceress and Wizard) and it comes from a outside place(Castle Grayskull of Eternia for He-Man and Rock of Eternity for Shazam). Both their powers can also be shared with other people.

Both part of a heroic team (Masters of the Universe and Justice League respectively) who protect the planet they reside (Earth and Eternia) against evil forces

Both can tap into their alter-egos by shouting a chant which gets them struck by a magical lightning (He-Man's "By the power of Grayskull..... I have the POWERRRRRRRRRR!" and Shazam's "SHAZAM!")

Both are considered rivals to a dark and equally powerful warriors that seeks to take their power and harness it for themselves and use it in a more unrestricted manner (Skeletor and Black Adam)

Both have a talking tiger as a sidekick (Battle Cat/Cringer and Mr. Tawky Tawny)

Both also have younger sisters who share their powers (Princess Adora/She-Ra for He-Man and Mary Marvel for Shazam)