I’m still not sure, but "Sorcerer's Kingdom" seam to be the nearest game to me.
Synopses: Monsters have begun to spread in the Kingdom of Landale...
Year of release in Japan: 1991
Year of release in US: 1992/3
Platform: Sega Megadrive/Genesis
Picture:
1st character: The hero's sprite seems to change while he equips with the various kinds of armors (it stays very different from the beginning. He also seems alis with that armor).
2nd character: Astina
3rd character: (he is under a tree, so we cannot see him)
4th character: Midi (not Miew)
There are a maximum of 4 characters and they can be reordered like PSIV. In the screenshots we can see Midi (the red girl that resembles Miew) and Astina (the woman with the yellow hair and red cape).