If I were to compile an actual list it would take a very long time, so just going to do off the top of my head.
Killing with a super results in the flash of the dead character's face like JJBA
TubaTubaTubaTuba, Band's level 5 time stop, Val's scalpels and the steamroller Peacock can drop are all JJBA references.
Beowulf has Talbain's Beast Cannon and even does the appropriate howls, his taunt is Talbain's Moment Slice and his "Gigantic Arm" is Slayer's Dead on Time, which is why some people call it Dead Arm Time.
Peacock's taunt is Tenrai Ha, and appropriately forces her Tenrai Ha drop.
Parasoul's level 3 is a super B.B. Hood has.
Robo-Fortune
Her button lay out works similarly to a Guilty Gear character's in general
MP is Makoto's MP
c.MP is Robo-Ky's
HK is Robo-Ky's Dust
j.HK is Robo-Ky's j.D
c.HK is similar to Robo-Ky's c.D
Has a Det mode, like Robo-Ky
Has Proton Cannon
Has Tager's Magnetism
Taunt input is Dan's suicide, because she's depressed.
Big Band has Q's drop kick, was the initial character with a taunt effect, has parried and shares a few other things with Q including that wonderful red color.
Squigly's taunt is the input for Shun Goku Setsu/Raging Demon, and we all know what else she shares in that regard. She uses Johnny's stance cancel mechanic and is far more patience based than most of SG's cast, much like Johnny is for Guilty Gear.
give this guy a metal. a metal made out of
tuna bacon
Metal is metal, friend. Perhaps a medal made of tuna bacon?