“Loki” didn’t deliver unqualified magic, but the Disney+ series was weird and inventive enough to cast a spell over fans, while introducing controversial actor Jonathan Majors’ mysterious villain into the Marvel universe. Returning after Majors’ theatrical debut in the less-than-scintillating “Ant-Man” sequel, the second season of “Loki” feels more assured and focused if still decidedly out-there, all while toting around its fair share of baggage.