I've opened a 10 + 1 relic pack for Squigly every time I could and I still don't have Bio-Exorcist. I've been trying since Squigly was first released (May) and before I knew she was really good; I initially just wanted her for her palette.
Others:
Beowulf - Dragon Brawler, Dark Might
Big Band - Private Dick, Megasonic, Heavy Metal
Cerebella - Heavy Handed, Brain Freeze, Toad Warrior
Double - Jawbreaker, Xenomorph
Eliza - Red Velvet, Stand Out
Filia - Windswept, Idol Threat, Class Cutter
Ms. Fortune - Meow 'n' Forever, Hack & Splash, Furry Fury
Painwheel - Firefly, Grim Fan, Fly Trap, Buzzkill
Parasoul - Star-Crossed
Peacock - Freeze Frame
Squigly - Necrobreaker, Bio-Exorcist, Love Crafted
Valentine - Last Hope, Pyrotechnique, Assassin's Greed
Others:
Beowulf - Dragon Brawler, Dark Might
Big Band - Private Dick, Megasonic, Heavy Metal
Cerebella - Heavy Handed, Brain Freeze, Toad Warrior
Double - Jawbreaker, Xenomorph
Eliza - Red Velvet, Stand Out
Filia - Windswept, Idol Threat, Class Cutter
Ms. Fortune - Meow 'n' Forever, Hack & Splash, Furry Fury
Painwheel - Firefly, Grim Fan, Fly Trap, Buzzkill
Parasoul - Star-Crossed
Peacock - Freeze Frame
Squigly - Necrobreaker, Bio-Exorcist, Love Crafted
Valentine - Last Hope, Pyrotechnique, Assassin's Greed