Let me start off with some basic ideas I had based on the Eclipse Spirits arc of the series.
Cana/scorpio- Soul card Trapping
Scorpio defeats Cana in the card duel and before cana can do anything else scorpio uses a card to trap Cana's soul inside. After Cana realizes that her mind is trapped in the card while her body is outside under scorpio's command. Scorpio has her body strip and then give him a blowjob, followed by a titjob before the real fun stuff. All the while Cana is stuck in the card able to feel whatever is being done to her body. After cumming in her pussy and asshole Scorpio gets hungry and decides to cook her in an oven he summons. Once he's done he takes out the card summons her and tells her until he dies he will use her and her body for food and pleasure and once he begins to die her summons her out, forces her to blowjob him and then burns her card killing her forever.
Sagittarius knocks out Erza then ties her down to a wooden horse stand. He then rapes her with his giant horse cock fucking her guts and cums inside her causing vomit it up. After he runs a far distance away and then shoots a thick pole at her. It enters her asshole and pierces her body ending at her mouth. He takes her to a bonfire and places her on as a celebration of his earned freedom and skill.
Mira/Pisces - roast beach
Pisces son rips apart mira's clothes and then starts to choke her out as her fucks her. When his mother come close enough he says that Mira is the one raping him causing his mother shark to get mad and charge at her as he pushes her off. She ripps off Mirajanes arms and legs. And then piscese sons brings her to the shore and spears her through her pussy, makes a big fire and grills her like a fish while his mother shouts out how she deserves all of this because she was a slut, whore, etc for "raping" her son.
Levy- Capricorn - rape grinder
Capricorn answers the final quiz question right so Levy is deemed the loser. As she's about to fall Capricorn commands the stage to stop and then has it restrain her by the arms and legs. He rips off her clothes and then forces her into different positions while he rapes her. After he's had his fun he then has the machine lift her up and lower her slowly over the grinding machine so her screams are nice and loud as she becomes burger meat for capricorn.
Juvia- Aries rape piss baked
Aries finds Juvia passed out in the desert. She takes her to a tent she set up and strips her naked binding her in magic sealing stone shackles. After when Juvia wakes up she sees Aries down a potion which gives her a giant cock. After Aries turns her over and starts raping her with extreme pain. Over and over she cums in Juvia, forcing her to lick her cock clean each time. After a while Aries starts to need the bathroom and then sees Juvia and knows exactly what to do. She forces Juvia down and forces her to eat her shit and makes her beg to drink her mistress' piss. After all of this Juvia faints from shock. When she awakes again she feels hot, Aries trapped her in a giant glass box surrounded by mirrors which cooks her using the desert sun. Juvia cooks alive and aries opens the box to enjoy her hot exotic meal as she strokes her cock thinking about her next meal and victim.