I'm thinking we could translate Yvette's surname as "Jacovy"
Gumina's dad's name is probably Classke
Sommy Hedgehog (gotta go fast)
Narcis' surname is spelled as Kissosu which is obviously a nod to Narcissus' real name "Narkissos"
Any suggetions open for Byakko
Marquis Donald's name is most likely a pun on Mc Donalds so i suggest Marks
Lari or Larry Lufic?
as for the poseesed people i suggest Aybee Cier and Barbara Baaba
"Rajih Assad", Assad is a common arabic surname
Gilles surname is a nod to the real Gilles surname "de Rais" so i suggest Derais
"Vlad Taberushi" into "Vlad Tabelsh"