Dark Half is a challenging RPG to play. Originally, it was only available for the Japanese Famicom market. However, it is now available in English.
In Dark Half, the player is a lone paladin named Falco. Falco is on his way to stop the return of an evil force sealed a long ago. Despite invoking and taking on the persona of his heroic god Roda, Falco fails and the demon king is released. The demon king’s earthly host Standard set up for this kind of game, however, after a brief scene where the demon king’s earthly host, assembles his servants and prepares to find and kill Falco/Roda for good, things go in a different direction.
Another cool RPG to consider is Secret of Mana II.