Swapping mates with my Twin sister

Samara bears an ugly birthmark while her twin Sienna is beloved by all beastmen. Phoenix Finn bonds with her only to use her as a spare for his true love Sienna. When Sienna’s dragon mate Alaric falls feral, Finn forces Samara to sacrifice herself in her sister’s place. Unexpectedly, Samara’s blood can cure the feral curse, and Alaric recognizes her as the prophesied goddess. Long-hidden childhood ties bind them, as Samara abandons the deceitful phoenix for the dragon who has silently loved her