Messibelle came to life due to Crafty's Infinium Heart.
Messi is a cocktail of different cleaning products, and it's possible that Crafty's homemade shampoo is the primary chemical in her composition. If he used the shampoo for more than decoration, then it washed away bits of his DNA down his drain. And that DNA could've been influenced by the Infinium Heart that replaced his original heart in his late teens. Plus, Messi is blue, like every other character tied to the Infinia — Sasha, Mindstein, and possibly Disgustilda. Thus, in a way, Messi truly is Crafty's blood-daughter.
Disgustilda's stupidity is an act.
With all the hints of there being more to Disgustilda than meets the eye, it's possible that she might be smarter than she lets on. She could be intentionally playing the fool; being easily defeated is all part of some master plan she has been brewing to get back at Crafty. After all, she does demonstrate some surprising insight in "I Need a Hero Academia," where she scolds Sasha for not reuniting with Crafty in person when she had the chance.
Mindstein is an Infinia.
"I Need a Hero Academia" reveals that Mindstein's current body is merely the latest one for a consciousness that has endured past its original body. Her build is somewhat identical to Sasha's — tall and lean — in addition to having blue skin. These qualities, combined with her vested interest in the Infinium relics, could mean that she is trying to start her race anew. As for why she's created so many different bodies for herself, she likely wants to distance herself from her heritage to keep as low a profile as possible. The more gods who know that she is an Infinia, the more unnecessary confrontations she'd have to deal with.
Disgustilda is an Infinia.
The Spin-Off Special has some freeze frame bonuses
resulting from Crystelle attempting to look into the future about Disgustilda becoming a legitimate threat. A few of the ones that aren't reused from past episodes show a titanic, silhouetted Infinia that doesn't seem to be Sasha. What's more, "We're Back! A Crafty Story" implies that something about Disgustilda continuously interferes with Crystelle's future sight. Whatever it is, something is up with this strange woman.
Metal Crafty will eventually betray Mindstein
Given that the madwoman forced Metal to watch the show on repeat, he's surely gotten a real axe to grind with her. That, along with the possibility of Screw coming upon him at the end of "Let's. Get. Metal.", Metal might come up with a plan to not only get rid of the Crafty Crew for good, but also Mindstein as revenge for what she did to him.
Pepper's character color might have something to do with her past.
Notice how, unlike all the other Crafty Crewmates, Pepper's character color does not match with anything on her color palette. She's chiefly pink, green, and a creamy yellow... but not maroon. She and Pickles converse about a "boil" ability, something that she swore off of doing many years ago, in the Spin-Off Special. Perhaps the color has something to do with that? After all, if Pepper were to, say, superheat her body, maroon would be a rather appropriate color for how she would look in such a state.
Pepper, as a primordial lifeform, is possibly some kind of deity, or at least some kind of ascended form of life.
Pepper's biology is a mystery to all who encounter her, her appetite is immense, and, if Metal Crafty's remark about her being a primordial lifeform in "Over the Moonsault" is to be believed, her lifespan extends so far back that she can't even remember most of it. Something's amiss with her origins, and while the Cthulu comparisons are easy to make, there could be a little more than that going on with Pepper, especially with how passive she is as a person. If she truly is some kind of powerful creature in that sense, it speaks highly of her character that she opts for such a selfless approach to life. She has all of that potential strength, and she dedicates it purely to cooking and making sure everyone around her is cared for.