Voice / Sound Effect sources:

Dex: just some dude. idk he never reached out to me to give me his name
Rena: Mai Nakahara - Higurashi Daybreak
Haruka Amami: Eriko Nakamura - The iDOLM@STER (various)
Riamu Yumemi: Seena Hoshiki - The iDOLM@STER: Cinderella Girls
Pyra: Skye Bennett - Xenoblade Chronicles 2, Super Smash Bros. Ultimate
Anila: Leona Renee - Granblue Fantasy Versus: Rising
Primarina: Pokemon (Generation 7) Sound Effects, Alfred Coleman/PaperBoxHouse
Bermudia: Cynthia Cranz - Yu Yu Hakusho