The internet is rife with MCU theories, especially what-if scenarios involving Thanos. Dedicated fans spend hours proposing compelling arguments about how the snap could've been avoided in Avengers: Infinity War if other Marvel characters had been present on Titan. One of the most commonly mentioned names is Ghost Rider.
Interestingly, it would've been entirely possible for Johnny Blaze, Danny Ketch or Robbie Reyes to appear in an MCU film, since the Ghost Rider rights reverted to Marvel Studios in 2013. Much like other characters such as the Punisher, Daredevil and Iron Fist, however, the powers-that-be decided to introduce the Reyes version on Agents of S.H.I.E.L.D. rather than bring him to the big screen.
Even so, it's fascinating to consider what sort of a threat Ghost Rider would pose to Thanos. While not a powerhouse like the Hulk or Colossus, the character possesses supernatural abilities -- the most formidable being the Penance Stare. To utilize this power, the Ghost Rider locks eyes with his target and makes them experience all the pain and suffering they've caused in their lifetime. It leaves the victim's soul permanently scarred and burnt from the agony.
Considering Thanos' initial reaction to sacrificing Gamora in Vormir, there's a belief that Ghost Rider could force the Mad Titan to come face to face with all the sorrow he's caused everyone else. It's plausible because it appears as if the villain has a heart somewhere underneath the layers of his megalomania. So, maybe the Spirit of Vengeance was all that was needed to prevent half of the Marvel Universe from being wiped out. The answer has already been revealed in the comics.
In Thanos #15, written by Donny Cates and illustrated by Geoff Shaw, the Mad Titan uses Cosmic Ghost Rider's skull to experience the Penance Stare. Rather than be overcome with emotion, he remarks that it's "beautiful." In that moment it's evident that Thanos doesn't feel any remorse for his actions; instead, he regards them as fond memories.
While the comic-book Thanos is significantly different from the MCU's version, they're similar in that they both do whatever it takes to get what they want. Therefore, it isn't hard to imagine that empathy is something that's sorely lacking in the character's composition. If he's ready to wipe out half the world -- including innocents and babies -- he's not exactly a paragon of virtue.
With the Penance Stare useless against Thanos, the Ghost Rider isn't the champion who would've put a stop to the villain's reign. There is another weapon, however, that could've proved useful in the Battle of Titan: The Rider's chain. It possesses the ability to transform into other weapons, but it's also virtually unbreakable.
On Titan the heroes struggled to hold back Thanos and remove the Infinity Gauntlet. If Ghost Rider had been present, his chain could've been the key to keeping the Mad Titan at bay. While it wouldn't have been a permanent solution, it would've given the Avengers more time to remove the Gauntlet, even after Peter Quill's silly actions.
Maybe all the Avengers required was a better strategy to take down Thanos. While Ghost Rider wouldn't have been the chosen one in the MCU, he certainly could've helped the team put up more of a fight.