Say Goodbye to Exodia!

It's frequently been noted that, compared to Weevil, Rex seems much less personally invested in the schemes to win back their former fame. For example, in Battle City, Rex doesn't seem to hold nearly as much of a grudge towards Joey as he goes on to display in Season 4. It's actually Weevil that's antagonizing Joey in that arc, meanwhile Rex actively tries to warn Joey away from engaging with Espa. The manga also notes in Rex's biography that, even though he's kind of obnoxious, he has the heart of a true duelist (paraphrased). It seems pretty obvious, at least to me, that he's mostly going along with this whole wannabe-villain thing out of loyalty to Weevil.

Though Orichalcos arc occasionally conflates Rex and Weevil's personalities in making them into a duo with a shared goal, I think the most consistent distinguishing factor between the two would have to be Rex's passivity versus Weevil's proactivity. This is demonstrated in both of the character's introductions: Weevil actively conspires to entrap Yugi while Rex is merely being used by Mai as a pawn in her feud with Joey. This characterization carries through to anime-exclusive Shrimp content, where Weevil is portrayed as the mastermind with Rex as an accomplice. Another key difference can be gleaned in how the two present their backstories during their Orichalcos duels. Weevil spends the entire time gloating to Yugi about revenge; Rex, on the other hand, at points seems stricken with grief remembering the hardships he and Weevil have endured. Rex and Weevil's differences in attitude are mirrored in how Yugi and Joey respectively respond to their tales of woe. Yugi shows no remorse in obliterating Weevil, while Joey tries to talk Rex down and even carries his limp body to safety after Rex loses his soul.

It's a pretty common interpretation that Rex and Weevil's friendship began out of convenience, like the two weird kids in class who had no friends being forced to play with each other despite not really getting along. I do believe these similarities are what initially brought them together, and certainly, I find the "you're the only one whose ever truly understood me" narrative to be very appealing, but I also think that differences are just as important to the foundation of a strong relationship. It is undeniable that Rex and Weevil's relationship goes beyond mere allyship over a common goal. Even if they might hesitate to admit it, they are clearly at least friends. So, beyond their surface level similarities, what is it exactly that Rex sees in Weevil, anyway?

This brings me to one of my favorite ShrimpShipping relationship dynamic headcanons, being that Rex is drawn to Weevil because of his conviction. As mentioned previously, Rex's primary reaction to losing his fame seems to be sadness and regret rather than anger. Before the Orichalcos arc, he expresses some annoyance and jealousy towards Joey, but never outright hostility. From this, as well as his overall passivity, I infer that Rex's first reaction to falling from grace would likely be resignment to his fate. After all, even at the peak of his popularity, he was only ever second-best. On some level, maybe he knew that it was all too good to be true. Rather than projecting the pain outwards, I imagine Rex directing it inwards. In other words, at least initially, Rex tore himself down instead of tearing down others, and that's where Weevil comes in.

Despite facing similar circumstances, unlike Rex, Weevil categorically refused to accept this fate, and he doesn’t refuse it only for himself but also on Rex's behalf. Though Weevil's scheming was certainly self-serving, the fact that he includes Rex at all indicates that it wasn't entirely so. You could argue that Weevil is simply using Rex for his personal gain, and though I would agree with you on some level, I'd also point out that nothing Rex and Weevil do in the Orichalcos arc actually requires two people (I think the only thing they do in the entire series that arguably does is when they impersonate that taller guy in the Grand Prix arc). This isn't like when Weevil bullied younger children into helping him cheat to take down Joey. Weevil doesn't benefit materially from including Rex in his schemes, however, I do believe that he benefits mentally, and I don't even just mean that in a "because he secretly likes him" way. Weevil just had everyone who had previously showered him in praise abandon him. The entire reason any of these hijinks ever happened is because Weevil is hurting from rejection, arguably to the point of trauma, so I think it makes perfect sense for him to cling onto Rex, and for Rex to do the same for the same reasons.

All of that is to say, when Weevil proposed the revenge scheme to Rex, it appealed to Rex for several reasons despite being something which he never would have thought to do himself. Considering that Rex saw no future for himself after losing his prestige, I think Weevil came to represent hope for him, and not even just because he promised a plan to return to their former glory. Weevil’s narrative of stolen valor implicitly suggested that he viewed Rex as someone fundamentally deserving. After losing everything and facing humiliation, scorn, and even violence for it, I can’t imagine how much it meant to him for Weevil to say “you didn’t deserve any of this.” While Weevil is undeniably taking advantage of Rex by using his sorrow and loneliness to serve his own revenge fantasies, I don’t believe that Weevil’s motivations were purely selfish, either. Weevil truly did believe that all his scheming would somehow work out in his favor, and even if it was only subconsciously, he wanted Rex to share in that success. That Rex was able to correctly identify Weevil’s soft spot for him is exactly what made him so loyal to Weevil in the first place, thus enabling Weevil to coerce him into villainous behavior. In turn, Weevil was able to rationalize projecting his worst impulses onto Rex by believing it was helping to Rex recognize his own worth.