I'm fighting against sleep rn but just know, there are multiple angsty Graecie centric fics where she gets badly injured/tricked/murdered by the double soul/ Doppelganger, beginning to take form in my ellipsus drafts.
Here's the first two ideas I had along this vein for those interested:
1. CPK isn't pranking Graecie and is actually a doppelganger/double soul that still lures her away from Legs and Sun Guard but actually successfully badly injures her in the dueling arena (still with crossbows and diamond knife). Cue Sun Guard and Legs running into the room (hearing her screams) just in time to see Graecie drenched in her own blood but with her new calm emotions spell unlocking (like how Legs' spell unlocked later) and her using it on the CPK double soul just in time to prevent it from killing her, and her sobbing and breaking down once Legs and Sun Guard kill the double. (Present tense for the suspense of her being in danger/risk of dying but also to signify she is able to change the outcome and survive, third person from Graecie's PoV)
2. Set at the same point as the above, but again CPK doesn't prank Graecie, and the double soul/doppelganger instead was appearing as Legs, and still lures her away from Real Legs and Sun Guard. Once again attacks her, aiming to kill (iron knife only, still no armour). However, this time she doesn't unlock her magic and her pov ends with the double soul/doppelganger standing over her prone body as she hears Real Legs' (and Sun Guard) sprinting into the room just seconds too late. Followed by Legs screaming her name and rushing to cradle her (and Fleece) in his arms, muttering reassurances under his breath as her consciousness fades away.
It then switches to Legs PoV as Graecie went after the double, showing him hearing her screams, sprinting in, seeing her bleeding on the ground with his double stood over her, bloody iron knife in hand. Legs rushes to her side, quickly realising the wounds are too fatal to save her life in time without healing magic, (which like in canon he doesn't have). And so instead he chooses to cradle her in his arms and whisper reassurances (whilst Sun Guard kills the double).
Potential bonus ending of the rest of the students nearby in the halls/main hall (if I remember correctly: Sausage, Zam, Pyro, Drift, Shelby, Scott, and CPK) reaching the classroom moments later and their reactions to Graecie (and poor Fleece since their bonded dragons share their life force) being dead, including the guilt from the latter who had pretended to be the double as a joke, now realising that it wasn't as harmless as they had thought). (Past tense for there's no saving Graecie, her fate has already decided and her death inevitable. Third person, starting with Graecie's PoV, then Legs'. If the bonus ending happens, can switch to a third PoV from among them for the extra guilt of their internal thoughts)