After the Sacred Whale Betrayed Me, I Contracted Poseidon

Layla is a contract mage. At a contract ceremony she binds herself to a beast, and in her first life she chose the Sacred Whale Neil and then spent that life gathering ninety-nine sacred cores so he could take human form. The moment he turned human he put a hole through her heart and pushed her into the Bloodtide Trench. She wakes on the day of the ceremony again. This time she walks past the Sacred Whale and picks a small spirit snake that is dying. Neil, human now, takes up with her sister Evelyn, and the two of them work at humiliating her in front of everyone. The snake is Poseidon, the Sea Emperor. Old betrayals come back into the open and Neil ends up on his knees about it, well after it can matter. Poseidon is the one who stays with her. Layla has decided she is finished spending herself on people who do not deserve it, and is learning to live for herself.