Summon Night Ecstasy: Yoake No Tsubasa

A spin-off to the Summon Night strategy-RPG games, SN Ecstasy is an action-RPG
in which you have direct real-time control of a unique character that actually
harbors the souls of both a male and female character. While you get to decide
who is the dominant personality for storyline purposes, you can transform
freely between both during gameplay as each has unique abilities and
individual experience levels that must be used to finish the game.

The game uses the same isometric 2D graphics as the strategy-RPG games, but
now everything moves in real-time and you have direct control of your attacks
and magic powers. Summoning creatures is possible but is mostly used as a
puzzle element to take advantage of the specific abilities of each creature.