-The Canopy Kingdon is in the Skullgirls's world equivalent to Europe. New Meridian and the Meridian Kingdom are equivalent to modern and ancient Italy respectively. Likewise, the Renoirs were orginally from the Northern Europe equivalent. Vitale calling the Renoirs "barbarians" and the their WWI-WWII German aesthetics reinforce this.
-Aeon is the most likeable and 'normal' of the Trinity. She has mundane interests and cares less about trying to kill everyone. Her personality is mostly shy and withdrawn, but a strongly obsessive and even possessive streak.
-The Aeon and Venus we see in Double's story are not exactly the same Aeon and Venus that Eliza killed.
-Everyone who goes to the Grand Cathedral regularly has questions regarding the strange and anachronistic fashion choices of the Venus stained glass.
-Queen Lamia and The Mother aren't exactly the same, either.
-Assuming Double is a construct of the Trinity and not something else (like a parasite), she's both the Skullgirls equivalent to an angel and Satan himself. She has a light color scheme with whites and golds, is a horrifying monster with multiple eyes that fulfills the work of god. And also the classical trickster and tempter with manipulates the evil in people and is the 'ruler' of the underworld (Gehenna).
-Double would absolutely dote on Umbrella almost as if she was her own daughter due to her appreciation of Umbrella's cataclysmic Skullgirl power and the fact that Umbrella might even qualify as a relative of Double.
-It is definitely not a coincidence that Valentine, Annie, Squigly and the Trinity statue are all missing an eye and that Parasoul (and Nancy), Double and Black Dahlia usually only have one eye showing.
-D. Violet is actually a bit of a lousy superhero and her escapades end up with her bound, gagged and hogtied more often than not.
-In addition to being patrons of the arts, the MEDICi are also big donors towards hospitals and medical research in the Canopy Kingdom. Which is a big reason as to why they were able to deduce that Eliza was stealing from the blood drives.
-Vitale is very aware of Cerebella's suspect feelings for him. He exploits these to keep her loyal and subservient to the mafia. Vitale meanwhile presents himself as an aloof father figure, but in truth he cares very little for Cerebella beyond her combat prowess and Vice-Versa.