Warning: SPOILERS for Superman & Lois season 2, episode 15 below!
Superman & Lois' season 2 finale secretly adapted the ending of Ang Lee's Hulk in its final showdown. In Superman & Lois' season 2 ending, after fully becoming Parasite, Ally Allston (Rya Kihlstedt) unleashes an apocalyptic plot to merge Earth with the Bizarro World. Having drained Superman (Tyler Hoechlin) of his powers, the Man of Steel and his half-brother Tal-Rho (Adam Rayner) devise a plan to swiftly recharge him by throwing Superman directly into the sun.
Their plan succeeds, with Superman emerging powered to enormous levels and intervening in Ally's merging of the two worlds. When Ally attempts to absorb Superman's powers again, this time, he simply places her hand to his chest and tells her to "Take some more." The amount of energy Superman is carrying proves to be too much for Ally to handle, enabling Superman to split the two merged Allys, and this isn't that far off from the finale presented by director Ang Lee in Hulk back in 2003.
In Hulk, David Banner (Nick Nolte) becomes Absorbing Man, with his son Bruce Banner (Eric Bana) morphing into the Hulk and the two battling, with David draining the Hulk's strength and taunting him with "The more you fight, the more of you I take." As the Hulk, Bruce then angrily tells his father, "You think you can live with it? Take it! TAKE IT ALL!" with David discovering he can't control the Hulk's power before the military deploys a gamma bomb on them. Superman & Lois runs with this idea in a more heroic context than the bitter ending of Hulk, but it also combines it with a major chapter of Kal-El's own history.
After dropping the two Allys back on Earth, Superman flies around the merging planets at super-speed, and with the solar energy he's absorbed, he punches the Earth so hard that it and the parallel Earth of the Bizarro World are finally separated for good. This part of Superman & Lois' season 2 ending adapts the ending of 1978's Superman. In that ending, after the demise of Lois Lane (Margot Kidder), the grief-stricken Superman (Christopher Reeve) flies around the Earth so fast that it spins in reverse, rewinding time and preventing Lois' death.
Since its beginning, Superman & Lois has been extremely reverential to the Last Son of Krypton's entire character history. This has extended to Superman's film and TV adaptations, with everything from the Christopher Reeve-led Superman movies to Zack Snyder's Man of Steel being given a loving tribute on the show. Reworking the ending of the 1978 Superman to fit its season 2 finale fits right in with Superman & Lois' style, but Marvel's big-screen legacy getting its own homage with Hulk's ending certainly was not something that ever seemed likely.
As Marvel's answer to Batman Returns, Hulk's extremely dour tone and cerebral ambiguity have made it a divisive pre-MCU Marvel film to this day. Still, like Superman himself, Superman & Lois sees the best in everyone, including in every comic book adaptation. In addition to Superman & Lois finally being confirmed to not take place in the Arrowverse, fans of both DC and Marvel got to see some nice Easter eggs to both Hulk and Christopher Reeve's first Superman movie, all wrapped in a quite epic mic drop moment of heroism from the Man of Steel.