Name spellings

Marsai
Marsei
Marcei

Fehra
Feyra
Fira
Fera

Isreoldai
Izreoldai
Isrealdai
Isreoldei
Izreoldei
Izrealdai
Isreolde
Izreolde
Isrealde

I’m not a fan of the letter Y.

With no other context I’d try Marseille, Fira and Isrioldae.